How to check a car’s paint and accident damage

Look first, measure second

A gauge only confirms what your eyes suspect. Look at a clean, dry car in daylight, in the open. Stand so the sun is behind you, then look across the panels from the side. Night, rain and dirt hide defects.

Panel gaps

Compare the gaps between the bonnet and the wings, the doors, the boot lid and the bumpers. On an undamaged car they are even along the whole seam, and the left side matches the right. A gap that is wide at one end and narrow at the other, or a panel that stands proud or sits low, points to a repair or a badly refitted part.

Colour and texture

Look along each side at a shallow angle. All the panels should have the same shade, the same gloss and the same fine texture, the “orange peel” of the paint. Look for runs, dust trapped in the clear coat and a different sparkle in metallic paint. Check in different light: some mismatches show only in direct sun.

Overspray and masking lines

A painter cannot mask everything. Look for a fine paint dust on the rubber seals of the windows and doors, on plastic trim, badges and the edges of the lights, inside the door shuts, under the edge of the bonnet and in the boot. Hard paint edges or masking-tape lines are further signs.

Hinge bolts and fasteners

Factory bolts are painted together with the body. Chipped paint or bare metal on the bolts of the bonnet hinges, the doors, the boot lid and the wings means they were undone: a panel was removed or replaced. Non-original bolts on the front panel or on the chassis rails are worse.

Using a paint thickness gauge

• It measures the total thickness of the coat on a metal panel, in micrometres (µm) or in mils (1 mil is 25.4 µm).
• Factory paint is typically about 100–150 µm (4–6 mils). Makes and panels differ, so compare the panels of the same car instead of trusting one number.
• A reading of about double the rest of the car, or above roughly 200 µm, suggests a repaint. Readings of several hundred µm suggest body filler under the paint.
• Very low readings can mean the paint was heavily polished or sanded through.
• Measure several places on every panel (edges, middle, lower part), including the roof and the pillars. A repainted roof or pillar often means a rollover or a heavy impact.
• Know the limits: a magnetic gauge does not work on aluminium (some bonnets, doors and wings are aluminium) or on plastic bumpers. Use a gauge that also reads aluminium, or rely on the visual checks.

Signs of structural repair

A small repaint of a bumper, a door or a scratch is common and not a reason to walk away if the price fits. Structural repair is different. Look for fresh or uneven seam sealer, welding marks or rippled metal in the engine bay, on the front panel and the chassis rails, in the door shuts and in the boot floor; non-original bolts; a bonnet or a door that does not line up. Check that the airbag covers on the wheel, the dashboard and the pillars sit flush and match: a replaced cover points to a crash with airbags deployed.

Tyres that wear unevenly, or a car that pulls to one side on a straight road, can point to bent suspension or a frame that was hit.

What to do with what you find

Ask the seller directly and ask for the repair invoice or the history. A small cosmetic repair with paperwork is fine and a fair reason to lower the price. Structural repair, a repainted roof or pillars, signs of deployed airbags, or a seller who denies what you can plainly see: walk away or have a bodyshop check the car. The rest of the checks are in How to check a used car before you buy it.