Index
Why Pre-Purchase Inspection is the Most Profitable Investment in Every Deal
Block 1: Documentation and Registry Status
Block 2: Vehicle History
Block 3: Visual Inspection of Bodywork and Cabin
Block 4: Basic Mechanical Inspection
Block 5: Margin Calculation Before Proposing an Offer
Red Flags That Should Make You Walk Away
How to Adapt the Inspection According to the Purchase Channel
Frequently Asked Questions
Why Pre-Purchase Inspection is the Most Profitable Investment in Every Deal
A 20-30 minute check before buying a car can prevent a €1,500 repair, a claim for hidden defects, or a vehicle stuck in stock for 90 days because it has a lien blocking the transfer. There is no other investment of time in the business with that return per minute.
The problem is that the pressure to close the deal, especially in fast channels like Wallapop or online auctions, leads to skipping steps. And the steps skipped during the purchase are exactly the ones that create the problems that appear when selling.
This checklist is organised into five blocks, ranging from the most urgent (what can make the deal unviable) to the most detailed (what refines the margin calculation). The order matters: if the first block raises red flags, the others do not need to be executed.
Block 1: Documentation and Registry Status
This is the first and most critical filter. A problem in this block can make the transaction directly unviable, regardless of how mechanically sound the car is.
Registered Owner. Verify that the seller is the registered owner in the DGT records or has power of attorney to sell on behalf of the owner. A seller who is not the registered owner cannot transfer the vehicle directly to you, and a deal closed without verifying this point can leave you with a car you cannot register in your name.
DGT Report. Request it before any financial commitment. The DGT report shows you active charges (seizures, reservation of title, impoundments), owner history, MOT (ITV) status, and pending fines that could block the transfer. It costs €8.67 and can save you weeks of administration. To understand what type of charges you might find and how to resolve them, you can consult the guide on how to find out if a car has liens or charges.
MOT (ITV). Verify if it is valid and when it expires. An expired MOT is not necessarily a reason not to buy, but it is an additional cost that you must incorporate into your margin calculation. Furthermore, a car with an expired MOT cannot be driven until it is renewed, which complicates transportation.
Municipal Road Tax (IVTM). If there are unpaid municipal road tax receipts for the current year, the local council can block the transfer until they are paid. Verify this with the corresponding town hall or through platforms that cross-reference this information.
Pending Finance. If the seller has active finance on the vehicle (retention of title), they cannot sell it to you without first cancelling that debt or coordinating the cancellation at the point of sale. Buying a car with an active retention of title without managing its cancellation is buying a problem.
Block 2: Vehicle History
With the DGT report in hand, the next step is to cross-reference it with the vehicle's actual history.
Mileage Consistency. The DGT report shows the mileage recorded at each MOT. Compare it with the current odometer reading. If there is a striking jump between two consecutive MOTs or if the odometer shows fewer kilometres than at a previous MOT, there has been odometer tampering. This is one of the most serious defects and the one that has the greatest impact on resale price and legal liability.
Accident History. A CARFAX or CarVertical report shows accidents recorded in international databases. It does not detect all accidents (those repaired without going through insurance are not recorded), but it does show those that went through insurance claims processing. A car with an accident in its history is not necessarily unsellable, but it is worth less and this must be disclosed upon sale.
Number of Owners and Frequency of Changes. A car that has had four owners in five years raising doubts about why it has rotated so much. There isn't always an underlying issue, but it is worth asking about.
Service History. A complete service book with stamps from the official network, or a verifiable digital history, proves that the car has received the maintenance appropriate for its mileage and age. Its absence does not imply that maintenance was not done, but it reduces the market price and increases the risk of future breakdowns.
Block 3: Visual Inspection of Bodywork and Cabin
The visual inspection takes between 10 and 15 minutes and provides significant details about the actual history of the vehicle.
Body Panels. Check the uniformity of gaps between panels (doors, wings, bonnet, boot). Irregular or asymmetrical gaps indicate post-accident repairs. Use a sidelight to detect ripples in the metalwork that are not visible in direct light.
Paintwork. Differences in tone or texture between adjacent panels indicate partial repainting, which may point to bodywork repairs. A paint thickness gauge (a €30-50 tool) gives the exact measurement of each panel and detects filler or resprays in seconds.
Angles and Frames. Door frames and the inside of the boot are the places where most evidence of accidents remains. A visible weld or deformation in a door arch are clear warning signs.
Glass and Seals. Cracks in the windscreen (even minor ones), deteriorated door seals, or moisture inside the cabin. A damp patch on the boot carpet or on the ceiling can indicate a sealing problem that lets water into the interior.
Cabin Condition. Upholstery, plastics, steering wheel, and pedals. The wear on the pedals and steering wheel must be consistent with the declared mileage. A very smooth steering wheel and highly worn pedals on a car with supposedly 60,000 km are a clear warning sign.
Block 4: Basic Mechanical Inspection
With all of the above reviewed, the mechanical inspection confirms or rules out the problems suggested by the documentation and visual check.
Cold Start. The engine should start smoothly and without excessive smoke. Bluish smoke indicates oil consumption. Persistent white smoke (not condensation from the first few seconds) may indicate a head gasket problem.
Fluid Levels. Engine oil (level and colour: black and clean is normal, cloudy or frothy indicates mixture with coolant), engine coolant (should not have traces of oil), brake fluid (level and colour).
Test Drive. At least 10-15 minutes in varied conditions: urban and highway, hard acceleration, progressive and emergency braking, tight turns to full steering lock to detect transmission noises. Listen actively: noises on bends (wheel bearings), vibrations under braking (warped discs), jerking when accelerating (transmission or clutch).
OBD Diagnostics. An OBD2 fault code reader (from €20) connected to the vehicle's diagnostic port shows active and stored faults. An active fault affecting critical systems (engine, transmission, ABS brakes, airbag) is a serious sign. Stored faults that are not active are less urgent but worth investigating.
For high-value or high-mileage vehicles. An inspection at a trusted garage before closing the purchase (€50-80) is an investment that pays off with the first unexpected surprise you avoid. If the seller refuses to let the car go through a workshop before the sale, that in itself is information.
Block 5: Margin Calculation Before Proposing an Offer
The check doesn't end with the car inspection. The final step, before making any offer, is to calculate the actual margin of the operation.
Expected selling price (based on current market prices for that model, year, and mileage on the portals where you will sell it) minus all costs: purchase price, cost of repairs detected in the inspection, preparation costs (valeting, photography), advertising costs on portals, transfer management costs, estimated financial costs (days it will take to sell multiplied by the cost of stock capital). The result is the actual net margin. If that margin does not reach the minimum you require per transaction, the purchase price must come down or the deal is not worth it.
To calculate the gross and net margin accurately and understand what factors erode it, you can review the guide on how to calculate the margin on used cars.
Red Flags That Should Make You Walk Away
There are situations where the smartest move is not to buy, regardless of the price.
A vehicle with a chassis number (VIN) that does not match the documentation exactly. An active registry lien/charge that the seller cannot cancel on the spot or prove is in the process of cancellation. An active engine fault code that the seller cannot explain. A mileage history that does not match the registered MOTs. A seller who cannot prove they are the registered owner or represent the owner. A price way below market value without a sensible justification.
In all these cases, the pressure not to miss out on the opportunity is your worst adviser. Problems bought at a bargain price are still problems.
How to Adapt the Inspection According to the Purchase Channel
Not all channels allow the same level of inspection, and the process must be adapted.
Buying from a private individual (Wallapop, Milanuncios): you have physical access to the vehicle before purchasing. You can complete the full checklist. Take advantage of it.
In-person Auction: there is a viewing period before the bidding session where you can inspect the vehicles physically. The inspection is more limited than in a direct purchase, but you can check the exterior, cabin, and start the engine. The DGT report must be consulted before bidding, not after.
Online Auction: you depend on photos, the operator's description, and the reports provided by the platform. For high-value vehicles, it is worth hiring a vehicle inspection service before bidding. For medium-priced cars with trusted operators, the history and detailed specification sheet are usually sufficient. To see how to structure the purchase process in auctions, you can consult the guide on car auctions for dealerships.
Renting and Fleets: the documentation and history are usually the most complete among all channels. Physical inspection is more important for detecting damage than for verifying its history.
More than 750 dealerships already use Dealcar to manage their daily operations
Dealcar allows you to query the DGT report directly from each vehicle's file, record the pre-purchase inspection results, and calculate the estimated margin before closing the purchase. With all information in one place, the buying decision is made with data, not intuition.
If you want to see how it works, you can book a free demo at dealcar.io.
Frequently Asked Questions
How long does it take to do a full inspection before buying a car?
With the five blocks, between 30 and 45 minutes for an average-priced car: 5 minutes for the DGT report, 10 minutes for the history, 15 minutes for the visual and basic mechanical inspection, and 5 minutes for the margin calculation. For cars over €15,000-20,000 or with high mileage, adding a garage visit extends the process but the investment is always justified.
Is it mandatory to request a DGT report before every purchase?
It is not required by law, but it is a practice that protects the dealership on multiple fronts: it detects liens/charges that would prevent the transfer, verifies the MOT status, and confirms that the seller is the registered owner. The cost is minimal (€8.67) and the information it provides is irreplaceable.
Is a car with active OBD faults always a problem?
It depends on the system affected and the severity of the fault code. An engine temperature sensor error might be an €80 repair. An active fault in the ABS braking system or the airbag is a safety issue that cannot be ignored. The key is to identify the fault before making an offer and factor the repair cost into your margin calculation.
Can I demand that the seller have the car checked in a garage before I buy it?
You can ask, but the seller is under no obligation to agree to it. If they refuse, you have to assess whether the risk without that inspection is acceptable at the offered price. At auctions, it is usually not possible. In direct purchases from private individuals or dealerships, it is a reasonable request for high-value cars.
Index
Why Pre-Purchase Inspection is the Most Profitable Investment in Every Deal
Block 1: Documentation and Registry Status
Block 2: Vehicle History
Block 3: Visual Inspection of Bodywork and Cabin
Block 4: Basic Mechanical Inspection
Block 5: Margin Calculation Before Proposing an Offer
Red Flags That Should Make You Walk Away
How to Adapt the Inspection According to the Purchase Channel
Frequently Asked Questions
Why Pre-Purchase Inspection is the Most Profitable Investment in Every Deal
A 20-30 minute check before buying a car can prevent a €1,500 repair, a claim for hidden defects, or a vehicle stuck in stock for 90 days because it has a lien blocking the transfer. There is no other investment of time in the business with that return per minute.
The problem is that the pressure to close the deal, especially in fast channels like Wallapop or online auctions, leads to skipping steps. And the steps skipped during the purchase are exactly the ones that create the problems that appear when selling.
This checklist is organised into five blocks, ranging from the most urgent (what can make the deal unviable) to the most detailed (what refines the margin calculation). The order matters: if the first block raises red flags, the others do not need to be executed.
Block 1: Documentation and Registry Status
This is the first and most critical filter. A problem in this block can make the transaction directly unviable, regardless of how mechanically sound the car is.
Registered Owner. Verify that the seller is the registered owner in the DGT records or has power of attorney to sell on behalf of the owner. A seller who is not the registered owner cannot transfer the vehicle directly to you, and a deal closed without verifying this point can leave you with a car you cannot register in your name.
DGT Report. Request it before any financial commitment. The DGT report shows you active charges (seizures, reservation of title, impoundments), owner history, MOT (ITV) status, and pending fines that could block the transfer. It costs €8.67 and can save you weeks of administration. To understand what type of charges you might find and how to resolve them, you can consult the guide on how to find out if a car has liens or charges.
MOT (ITV). Verify if it is valid and when it expires. An expired MOT is not necessarily a reason not to buy, but it is an additional cost that you must incorporate into your margin calculation. Furthermore, a car with an expired MOT cannot be driven until it is renewed, which complicates transportation.
Municipal Road Tax (IVTM). If there are unpaid municipal road tax receipts for the current year, the local council can block the transfer until they are paid. Verify this with the corresponding town hall or through platforms that cross-reference this information.
Pending Finance. If the seller has active finance on the vehicle (retention of title), they cannot sell it to you without first cancelling that debt or coordinating the cancellation at the point of sale. Buying a car with an active retention of title without managing its cancellation is buying a problem.
Block 2: Vehicle History
With the DGT report in hand, the next step is to cross-reference it with the vehicle's actual history.
Mileage Consistency. The DGT report shows the mileage recorded at each MOT. Compare it with the current odometer reading. If there is a striking jump between two consecutive MOTs or if the odometer shows fewer kilometres than at a previous MOT, there has been odometer tampering. This is one of the most serious defects and the one that has the greatest impact on resale price and legal liability.
Accident History. A CARFAX or CarVertical report shows accidents recorded in international databases. It does not detect all accidents (those repaired without going through insurance are not recorded), but it does show those that went through insurance claims processing. A car with an accident in its history is not necessarily unsellable, but it is worth less and this must be disclosed upon sale.
Number of Owners and Frequency of Changes. A car that has had four owners in five years raising doubts about why it has rotated so much. There isn't always an underlying issue, but it is worth asking about.
Service History. A complete service book with stamps from the official network, or a verifiable digital history, proves that the car has received the maintenance appropriate for its mileage and age. Its absence does not imply that maintenance was not done, but it reduces the market price and increases the risk of future breakdowns.
Block 3: Visual Inspection of Bodywork and Cabin
The visual inspection takes between 10 and 15 minutes and provides significant details about the actual history of the vehicle.
Body Panels. Check the uniformity of gaps between panels (doors, wings, bonnet, boot). Irregular or asymmetrical gaps indicate post-accident repairs. Use a sidelight to detect ripples in the metalwork that are not visible in direct light.
Paintwork. Differences in tone or texture between adjacent panels indicate partial repainting, which may point to bodywork repairs. A paint thickness gauge (a €30-50 tool) gives the exact measurement of each panel and detects filler or resprays in seconds.
Angles and Frames. Door frames and the inside of the boot are the places where most evidence of accidents remains. A visible weld or deformation in a door arch are clear warning signs.
Glass and Seals. Cracks in the windscreen (even minor ones), deteriorated door seals, or moisture inside the cabin. A damp patch on the boot carpet or on the ceiling can indicate a sealing problem that lets water into the interior.
Cabin Condition. Upholstery, plastics, steering wheel, and pedals. The wear on the pedals and steering wheel must be consistent with the declared mileage. A very smooth steering wheel and highly worn pedals on a car with supposedly 60,000 km are a clear warning sign.
Block 4: Basic Mechanical Inspection
With all of the above reviewed, the mechanical inspection confirms or rules out the problems suggested by the documentation and visual check.
Cold Start. The engine should start smoothly and without excessive smoke. Bluish smoke indicates oil consumption. Persistent white smoke (not condensation from the first few seconds) may indicate a head gasket problem.
Fluid Levels. Engine oil (level and colour: black and clean is normal, cloudy or frothy indicates mixture with coolant), engine coolant (should not have traces of oil), brake fluid (level and colour).
Test Drive. At least 10-15 minutes in varied conditions: urban and highway, hard acceleration, progressive and emergency braking, tight turns to full steering lock to detect transmission noises. Listen actively: noises on bends (wheel bearings), vibrations under braking (warped discs), jerking when accelerating (transmission or clutch).
OBD Diagnostics. An OBD2 fault code reader (from €20) connected to the vehicle's diagnostic port shows active and stored faults. An active fault affecting critical systems (engine, transmission, ABS brakes, airbag) is a serious sign. Stored faults that are not active are less urgent but worth investigating.
For high-value or high-mileage vehicles. An inspection at a trusted garage before closing the purchase (€50-80) is an investment that pays off with the first unexpected surprise you avoid. If the seller refuses to let the car go through a workshop before the sale, that in itself is information.
Block 5: Margin Calculation Before Proposing an Offer
The check doesn't end with the car inspection. The final step, before making any offer, is to calculate the actual margin of the operation.
Expected selling price (based on current market prices for that model, year, and mileage on the portals where you will sell it) minus all costs: purchase price, cost of repairs detected in the inspection, preparation costs (valeting, photography), advertising costs on portals, transfer management costs, estimated financial costs (days it will take to sell multiplied by the cost of stock capital). The result is the actual net margin. If that margin does not reach the minimum you require per transaction, the purchase price must come down or the deal is not worth it.
To calculate the gross and net margin accurately and understand what factors erode it, you can review the guide on how to calculate the margin on used cars.
Red Flags That Should Make You Walk Away
There are situations where the smartest move is not to buy, regardless of the price.
A vehicle with a chassis number (VIN) that does not match the documentation exactly. An active registry lien/charge that the seller cannot cancel on the spot or prove is in the process of cancellation. An active engine fault code that the seller cannot explain. A mileage history that does not match the registered MOTs. A seller who cannot prove they are the registered owner or represent the owner. A price way below market value without a sensible justification.
In all these cases, the pressure not to miss out on the opportunity is your worst adviser. Problems bought at a bargain price are still problems.
How to Adapt the Inspection According to the Purchase Channel
Not all channels allow the same level of inspection, and the process must be adapted.
Buying from a private individual (Wallapop, Milanuncios): you have physical access to the vehicle before purchasing. You can complete the full checklist. Take advantage of it.
In-person Auction: there is a viewing period before the bidding session where you can inspect the vehicles physically. The inspection is more limited than in a direct purchase, but you can check the exterior, cabin, and start the engine. The DGT report must be consulted before bidding, not after.
Online Auction: you depend on photos, the operator's description, and the reports provided by the platform. For high-value vehicles, it is worth hiring a vehicle inspection service before bidding. For medium-priced cars with trusted operators, the history and detailed specification sheet are usually sufficient. To see how to structure the purchase process in auctions, you can consult the guide on car auctions for dealerships.
Renting and Fleets: the documentation and history are usually the most complete among all channels. Physical inspection is more important for detecting damage than for verifying its history.
More than 750 dealerships already use Dealcar to manage their daily operations
Dealcar allows you to query the DGT report directly from each vehicle's file, record the pre-purchase inspection results, and calculate the estimated margin before closing the purchase. With all information in one place, the buying decision is made with data, not intuition.
If you want to see how it works, you can book a free demo at dealcar.io.
Frequently Asked Questions
How long does it take to do a full inspection before buying a car?
With the five blocks, between 30 and 45 minutes for an average-priced car: 5 minutes for the DGT report, 10 minutes for the history, 15 minutes for the visual and basic mechanical inspection, and 5 minutes for the margin calculation. For cars over €15,000-20,000 or with high mileage, adding a garage visit extends the process but the investment is always justified.
Is it mandatory to request a DGT report before every purchase?
It is not required by law, but it is a practice that protects the dealership on multiple fronts: it detects liens/charges that would prevent the transfer, verifies the MOT status, and confirms that the seller is the registered owner. The cost is minimal (€8.67) and the information it provides is irreplaceable.
Is a car with active OBD faults always a problem?
It depends on the system affected and the severity of the fault code. An engine temperature sensor error might be an €80 repair. An active fault in the ABS braking system or the airbag is a safety issue that cannot be ignored. The key is to identify the fault before making an offer and factor the repair cost into your margin calculation.
Can I demand that the seller have the car checked in a garage before I buy it?
You can ask, but the seller is under no obligation to agree to it. If they refuse, you have to assess whether the risk without that inspection is acceptable at the offered price. At auctions, it is usually not possible. In direct purchases from private individuals or dealerships, it is a reasonable request for high-value cars.
