I used to build car audio systems so I have seen a LOT of weird stuff in cars. Anyone who has to professionally disassemble a vehicle’s interior will likely have some horrifying stories of things they have uncovered. More than once I have refused work unless customers had their vehicles professionally cleaned. Some of the things I have found include:

piles of actual, un-bagged trash (some of it was being used to hold up the driver’s seat back rest as it had broken)

big fuzzy mounds of fungus growing under the seats

standing liquid (I don’t know what it was, but it wasn’t clear)

a dildo that looked visibly unclean

a condom (unwrapped)

an actual live bat that was apparently living above the drivers footwell (it fell down onto the floor mat, looked up in surprise and flew away).

A revolver hidden beneath the center console.

With the exception of the bat, I immediately refused work until the vehicle was professionally cleaned (or the potentially illegal weapon removed).