Look at the seat rails and seat mounting brackets. They're pretty much never galvanized, just painted a light matte black and work great as slow acting moisture detectors. Trim covers them up these days, but move the seat all the way forwards or back and you'll usually either see some of that metal or be able to get to a position where you can. They'll also rust over time due to long term high humidity from a leaking window or door seal, or shoddy crash repair, or a slow leak from the heater core, so even if it's not flood damage there might be other issues.

you remove the seats?

LOL What? Do you seriously remove the driver's seat when you are car shopping?

Don't you lol what me. You are making this about car shopping. mmaunder wrote about removing the carpet to clean. Ofc you don't remove the carpet of a car you want to buy. I would never had guessed that you meant 'see the metal' in a car shopping context, as it's as easy as breathing to flip some carpet over and get a sense of the floors state.

mmaunder also wrote:

> A really great check to do if you're buying used is to look under the driver's seat for rust. It indicates flooding. In the case of pickups, it means they either submerged it or used it as a mudder. Red flag. Walk away.

which is probably what the parent post was addressing with how do you check this?

You just slide it back all the way and then slide it forward all the way.