Buying used: the questions a seller hopes you will not ask

Almost everything that goes wrong with a used car purchase was visible before the money moved. Not to a specialist eye — to anyone who looked in the right order, without hurrying, in daylight.

Two rules before anything else. Never view a car in the rain: water fills the fine texture differences that give away a repainted panel, and it flatters every scratch. Never view one after dark. If the only slot the seller offers is 8pm in November, that is information too.

The point of what follows is not to turn you into a mechanic. It is to decide whether this particular car has earned an hour of a professional's time on a lift.

Before you leave the house

• Run whatever vehicle history check exists in your country, using the identifiers in the advert rather than ones the seller reads out later
• Check for outstanding finance, insurance write-off records, and a stolen marker — the seller cannot pass clean title if a lender still has an interest
• Look up the mileage history if your country publishes past inspection readings; the shape of the curve matters more than any single number
• Read owner forums for the known weak points of that engine and gearbox family
• Price the expensive scheduled jobs for that engine — a timing belt, a clutch — before you fall for the car

Then ask one thing explicitly when you arrange the viewing: please leave it cold, I would like to start it myself. A warm engine hides smoke, rattles, and a battery that no longer wants to turn it over. A seller who has thoughtfully warmed it up may be being polite. Come back another day and find out.

Paperwork before metal

Check the registration document first, while you are still capable of walking away. The name and address on it should match the person standing in front of you and the house you are standing outside. Match the vehicle identification number on the document to the one on the car — usually visible at the base of the windshield, repeated in the door aperture, often stamped under the hood or beneath the trunk floor. They should all agree, and none should look disturbed.

With service records, continuity beats volume. A thin folder with an unbroken sequence of dates is worth more than a fat one with a two-year hole in it. Read the mileages across the invoices and see whether they describe a plausible life. Look specifically for the big scheduled items, and for whether they were done on time or a long way past.

The walk around

Stand at one corner and sight along the flank so the reflections stretch out down the body. Ripples that are invisible head-on show up immediately in a long reflection. Work around all four corners. Compare each panel gap with the same gap on the other side of the car rather than with an idea of what is normal. Look for a different paint texture on one panel, overspray on rubber seals, and bolt heads on hinges and fenders where the paint has cracked — a bolt that has been undone was undone for a reason.

Then the tires, which are the most honest part of any car. Four different brands means someone bought whatever was cheapest, one at a time. Mismatched tires across a single axle is worse. Uneven wear across the tread points at alignment or suspension trouble, and the date codes tell you whether the fresh-looking rubber is actually fresh. A car with a spotless history file and four budget tires is telling you two different stories.

Rust is the one to be careful about, because the surface kind and the structural kind look similar to an untrained eye and are not the same problem at all. Check wheel arch lips, the bottoms of doors, sills, the trunk floor under the mat, and the spare wheel well for standing water. Bubbling paint means corrosion working outward from underneath. Anything at a suspension mounting point or on a structural member is not a haggling point, it is a stop sign — walk away, or make the sale conditional on a proper inspection.

Inside

Interior wear should tell the same story as the odometer. A shiny steering wheel rim, worn pedal rubbers, a collapsed driver's seat bolster and a polished gear lever belong to a high-mileage car regardless of what the display says. Sniff for damp and press the carpets in the footwells and the trunk with your palm. Water leaks are miserable to trace and they ruin electronics slowly.

Then work through the switches methodically: every window, both mirrors, central locking, every wiper speed, the washers, the air conditioning left running long enough to prove it gets properly cold, heated seats, the screen. Have the seller stand outside while you run through all the lights, reverse and fog included.

One check people miss: turn the ignition on without starting the engine and watch the instrument cluster. The airbag, ABS and engine warning lamps should all light up and then go out once it starts. A lamp that never illuminates at all has sometimes been persuaded not to.

The drive

1. Start it yourself from cold and watch the mirror for the first thirty seconds — a puff on start is common, continuous smoke is not
2. Let it idle while you listen with the hood up, then close it and drive with the radio off and a window down
3. Get up to a proper road speed rather than circling the block; vibrations appear above town speeds
4. On an empty stretch, brake firmly once in a straight line: it should stop straight, without pulling, shudder or noise
5. In a quiet lot, turn to full lock both ways at walking pace and listen for clicking or knocking
6. Reverse, park, then go back and look at the ground where it was standing

Afterward, open the hood again and look for fresh wet residue around hose joints, the oil filter and the water pump area. Creamy deposits under the oil filler cap are worth a question rather than a verdict — on a car used for short trips it is often just condensation, but combined with coolant that keeps disappearing it means something else.

Where to stop and hand it over

There is a point where amateur inspection stops being useful and starts being dangerous. Brakes, suspension, steering components, structural corrosion and evidence of accident repair need a lift, proper lighting and someone who looks at ten cars a week. An independent pre-purchase inspection typically costs a fraction of one unexpected repair, and it either gives you a stronger negotiating position or saves you the whole amount. Do not go under a car yourself on a driveway jack to find these things out.

If a private seller refuses an independent inspection, or a dealer will only allow one from a shop they nominate, you already have the answer and it did not cost you anything.

Set your walk-away number before you arrive and tell someone else what it is. The strongest position in any used car negotiation is a genuine willingness to look at the next one instead.