Buying a Used Car: The Checks Worth Doing

Before you go anywhere, get the history report

Do this before you view the car, not after you have fallen for it. A history check run against the registration and VIN will tell you whether the car has outstanding finance on it, whether it has been written off and repaired, whether the mileage recorded now is lower than a mileage recorded at some point in the past, and whether it is registered as stolen. Any one of those four things is a reason to walk away, not a reason to negotiate harder.

Ask the seller for the registration number and the VIN before you commit to a viewing. A private seller who will not give you either is not worth the drive.

What a pre-purchase inspection actually covers

If the car passes the history check, the next step is a proper inspection, not a walk around the forecourt. You have two options: pay a mechanic to inspect it before you buy, or do a structured check yourself if you know what you are looking for. A paid inspection costs money you do not get back if you walk away from the car, but it costs far less than discovering a head gasket problem after you have paid for the car.

If you are doing it yourself, work through this order every time, on every car, so you do not skip a step because the seller is chatting to you:

Check the paint in daylight, not under a forecourt canopy. Look along the length of each panel at a low angle. A slightly different shade or texture on one panel usually means it has been resprayed after damage.
Check panel gaps. The gap between the bonnet and the front wings, and between each door and its neighbouring panel, should be even on both sides of the car. An uneven gap suggests either poor factory tolerance or a panel that has been replaced.
Open the bonnet and look for fresh clips, mismatched paint on brackets, or a valeted engine bay on an otherwise ordinary car. A recently steam-cleaned engine on a car that has clearly not been detailed anywhere else is sometimes an attempt to hide a leak.
Check the tyres, including the spare. Uneven wear across the width of a tyre points to a suspension or alignment problem. Different brands or wear levels front to back are not disqualifying on their own, but ask why.
Check the tailpipe. Black, oily soot suggests an engine burning oil. This is a rough guide, not a diagnosis, but it is worth noting before the test drive.

The test-drive checks a non-mechanic can actually do

You do not need to know how an engine works to notice when something is wrong. You need to slow down and pay attention to things you would normally ignore.

Start the car from cold if at all possible. Ask to see it before it has been running. A cold start reveals smoke, rattles and warning lights that a warmed-up engine can hide. If the seller has conveniently already warmed it up before you arrive, that is worth noting.
Watch the dashboard for warning lights at start-up, and check they all extinguish after a few seconds, as they are designed to.
Drive on a road with some bends and a bit of speed, not just the seller's street. Motorway or dual-carriageway access matters here. Problems with wheel bearings, alignment and vibration often only show up above town speeds.
Brake firmly from a reasonable speed in a safe spot. The car should pull up straight, without pulling to one side or vibrating through the pedal.
Turn the wheel fully to each lock at low speed and listen for clicking. A clicking noise on full lock is a common sign of a worn drive shaft joint, which is a real repair cost, not a cosmetic one.
Turn everything off, then turn everything on. Aircon, heated seats, all the windows, the infotainment screen, reversing camera if fitted. Small electrical faults are cheap to ignore and expensive to fix later, and sellers rarely mention them unprompted.
Drive with the radio off for part of the test. Knocks, whines and grinding noises are far easier to hear without music covering them.

Negotiating position: what actually moves the price

The biggest lever you have is time. If you need a car this weekend, you have already told the seller that in how you talk about the car. Try to view more than one car in the same window so you are not pricing against a single option you have already decided to want.

Any fault you find during the inspection or test drive is a specific, named reason to reduce the offer, and it lands better than a general "can you do any better on price." If the tyres need replacing within a few thousand miles, say so and name the number of tyres. If the service history has a gap, point at the gap. Sellers expect a number pulled from nowhere and are used to rejecting it. A number attached to a fact is harder to wave off.

Decide your ceiling before you start talking, not during the conversation. It is easy to creep upward in small steps once you are standing next to a car you like.

The paperwork traps

The paperwork stage is where a good car and a bad decision can still coexist, so slow down here even if everything so far has gone well.

Match the VIN on the vehicle to the VIN on the registration document, in person, before you pay. Do this even though the history check already confirmed the VIN. It confirms the document in front of you belongs to the car in front of you.
Confirm the name on the registration document matches the seller's ID. If a private seller is not the registered keeper, ask why, and get a clear answer before you continue.
Get any outstanding finance cleared or confirmed as cleared in writing before money changes hands, even if your history check came back clean. Checks are a snapshot, not a guarantee, and finance can be settled at different speeds by different providers.
Get a signed and dated receipt that states the sale price, the mileage at sale, and both parties' names, even for a private sale between individuals who trust each other. This protects you if the mileage is later disputed.
Do not hand over full payment before you have the keys, the documents, and a completed change of ownership in hand. A deposit to hold a car is normal. Paying in full and collecting later is not.

This week

Before you view another car, write down the registration and VIN check as the first step, not something you do "if it looks promising." Making it the very first action, before you have seen a single photo of the interior, keeps you from getting attached to a car you have not yet confirmed is what it claims to be.