“No accidents, one owner” - and half of those listings are lying. A car after proper bodywork can look better than the original. The problem is that a poorly repaired accident car means reduced body rigidity, corrosion in repaired areas, and the risk that airbags won’t deploy properly in the next crash.

The good news: bodywork can’t be hidden from someone who knows where to look. Here’s the inspection order I use - it takes 20 minutes and catches 90% of repairs.

First: where the car came from

Before you touch the panels, check the origin. Cars from US salvage auctions (Copart, IAAI) sold as “salvage/totaled” are a verdict - someone bought them cheap, patched them up and imported them. You can find this by VIN (search “VIN [number] copart” or use an aggregator). If the car appears on a salvage auction, the rest of the inspection is just assessing how well it was repaired.

1. Paint thickness - the gauge is essential

The most important tool. A cheap paint thickness gauge measures the coating layer in micrometers (µm).

Approximate thresholds:

80-150 µm - factory paint, OK.
150-300 µm - repainted panel (minor repair, chip, scratch). Not necessarily an accident, but worth asking.
300+ µm - thick filler, serious bodywork. Red flag.
Jumps of hundreds of µm between adjacent panels - one was repaired, the other wasn’t.

Measure every panel separately: hood, roof, trunk, all four fenders and doors. Do it systematically - 3-4 points per panel. The roof and pillars are structural; a thick layer there is the worst sign.

In MotoPPI you get an interactive car diagram - tap a panel, enter the reading, and the app instantly colors it green/yellow/red against these thresholds and compiles it into a report.

2. Panel gaps and seams

The factory assembles a car to millimeter precision. After bodywork, seams rarely return perfectly.

Look at the gaps between hood and fenders, doors and arches, trunk and rear fenders.
They should be even on both sides of the car. A hood gap narrower on the left than the right = the front was reassembled.
Uneven gap, too wide, a “step” between panels - a sign of repair.

Trick: crouch by the corner of the car and look along the side - a wave in the metal, an uneven light reflection reveals filler and straightening.

3. Bolts and fasteners

Factory bolts are painted together with the body - they have untouched paint on the head. If a bolt was undone (replacing a fender, hood, bumper), the paint on it is scratched, scraped or re-tightened.

Check the bolts on:

hood and trunk hinges,
fender mounts (under the hood, by the arches),
the front slam panel.

Scuffed marks on bolts = the panel was removed. Not necessarily an accident (sometimes service), but combined with thick paint - the picture comes together.

4. Glass brand and production dates

Every pane has a manufacturer mark and production date (dots + a digit). In a factory car all panes are the same maker and from a similar date (before the car’s build date).

One pane of a different brand or a much later date = it was replaced. Windshield - maybe a stone. But a side or rear pane replaced is often a sign of a crash or break-in.
Compare the tint and logo on all the glass.

5. Welding marks and non-factory sealant

Open the doors, trunk and hood and look into the sills, recesses and edges.

Factory spot welds are even and regular. A continuous, uneven, ground-down weld = the body was cut and welded (serious structural repair).
Factory sealant (on panel joins) has a characteristic, even bead. Sealant applied by hand, uneven, fresher = someone worked here.
Corrosion in unusual places (inside the arch, on the door edge) - repair without anti-corrosion protection.

6. Trunk and spare wheel

Lift the trunk liner and check the spare wheel well:

even metal, straightening marks, fresh paint = a rear impact,
buckled floor metal = a serious rear collision.

This area is rarely cosmetically fixed, because it’s not visible at first glance.

7. Lights and their mounts

A new light in an old car (clean, no scuffs, a different plastic tint than the rest) next to old ones = replaced after a knock. Also check the clips and mounts - broken, glued, zip-tied = removed after an impact.

What you won’t catch with the naked eye

Some things need a lift and a mechanic:

suspension geometry (the car “pulls” - the body may be bent),
frame / chassis rail condition from below,
whether airbags work (after a crash they’re sometimes not replaced - the SRS light must go out after startup).

If the on-site inspection raises doubts, the next step is a mechanic with a lift (a small cost relative to the decision to spend tens of thousands).

Summary - the order

Check origin (US auctions, history) before you set off.
Paint gauge on every panel.
Seams and gaps - symmetry.
Bolts - signs of removal.
Glass - maker and dates.
Welds, sealant, corrosion in recesses.
Trunk and wheel well.

An accident car isn’t always a dealbreaker - a well-repaired car after a minor knock can be fine and cheaper. The point is to know what you’re buying and negotiate the price accordingly, not to pay “no-accident” money for a car that isn’t.