How to spot flood damage in auction photos

Flood cars reach wholesale lanes every year, and they reach them looking ordinary. A competent detail hides most of what water does to an interior, which is exactly why the evidence that survives is worth knowing: it sits in the places a detailer has no reason to reach.

You cannot diagnose a flood car from a photo set. You can decide, from a photo set, that this is not a car to spend your inspection time on.

Water settles low and stays

Everything useful follows from one fact: water finds the lowest enclosed point and sits there. So the evidence is low, enclosed, and awkward to clean.

• Seat rails and their bolt heads. Bare steel under a carpet edge rusts quickly and is never polished. Orange on a bolt head in a car with a tidy interior is a contradiction worth resolving.
• The spare wheel well. The lowest enclosed point in most vehicles. Silt or a tide line here is the closest a photograph gets to a straight answer.
• The sill under the carpet edge. Where the carpet meets painted metal at the door opening, visible in a good interior shot with the door open.
• Seat belt webbing. Water wicks up a belt and dries as a stain. A belt photographed at full extension sometimes shows a line the retracted belt hides.

The tide line is the tell

A tide line is a horizontal mark at a consistent height, and consistency is what distinguishes it from ordinary grime. Dirt is random. A water line is level, and it is level at the same height on the left and the right of the car, because the car sat flat in the water.

If you can see a mark at the same height on two opposite sides of the interior, you are looking at something that filled rather than something that spilled.

Corrosion where it has no business being

Rust under a car is normal. Rust inside a car is not. The signal is not corrosion itself, it is corrosion in a place that stays dry in a car that has lived a normal life:

• Bolt heads and brackets under the seats
• The metal frame of the seat itself, visible from behind in a rear-seat photograph
• Door hinges and striker pins, which are painted and should not bloom
• Screw heads inside the door jamb

A single rusty fastener is a repair. Several, all at a similar height, in a car whose exterior is clean, is a pattern.

Fogged lamps and hazy glass

Sealed housings that took on water often keep a little. A headlamp or tail lamp with moisture or a dried mineral haze inside, in a car with no accident history to explain a reseal, is worth noticing. So is interior glass that looks permanently filmed: flood residue on the inside of a windscreen is difficult to remove and photographs as a dullness rather than as dirt.

What the photographs cannot show, and why it decides

Every expensive consequence of a flood is invisible to a camera. Corroded connector pins, a control module that works today, a wiring loom wicking moisture inside its insulation: these fail weeks or months later, on somebody else's lot, after you have sold the car.

That is the reason flood is different from collision damage. A creased quarter panel has a price. A flooded loom has a probability, and the probability is against you.

The order to work a set in

1. Spare wheel well, cover lifted, if the set has it
2. Seat rails and bolt heads, enlarged
3. Door sills with the door open, both sides, comparing heights
4. Lamps and interior glass for haze
5. Any photograph taken from below seat height, which is where a careless set gives it away

Find two of those and stop. The correct response to photographic flood evidence is not a lower bid: it is the next listing.