Wow, That's crazy! I had a customers car come in with the bucket seats lag bolted to the floor.

Sort of a different thing but we once found a snake inside a seat.
Johann
www.coachtrim.com

A used condom is probably the most dangerous thing I’ve found

In a '65 Lincoln that had been brought up from the states, found a 9mm handgun in the trunk way down in behind the right rear wheel well.
Fully loaded with one in the chamber. The safety was NOT on!
But...it had been in there soo long that it just looked like a big chunk of rust. The inside of the barrel was a solid mass of rust. Corroded solid.
The car had even been inspected at the border when it was imported. The border guards don't usually miss stuff like that!
Other than the police here having them, a 9mm is not a common sight, up here in Canada.

...

*Picks up the phone*
"Hello. Yes, please pick up your car immediately."
"No, I will not be able to complete the job."

yeah, I wish I didn’t need the money back then and I would’ve done exactly that

My guy just found the starting of a wasps nest in the front rest of a 55 Chevy.

I find lots of those - I do a lot of farm vehicles that get used once a year

I find a few of those a year too. Don’t forget the mummified mice and their droppings

Live Scorpions. The customer was storing the seats in his garage and they made them their home. I found 6 in 2 bucket seats. It's Arizona, it was their home first.

Actually the hard wired harness above may have come that way from the factory.
I've run into that on several GM SUVs, in the past year or two.
The first time I assumed that someone had rigged it up but after seeing several more , and noticing how the wiring was very neatly done and so neatly wrapped up with cloth tape I figured something else was up.
So I asked the dealership about it , they told me that apparently the factory had some issue the disconnects on some models for a few years (?) and they just hardwired the airbag wires.
To do the work I cut the leads, did the upholstery work, then resoldered and shrink wrapped the wires like before.

On one job that I did, I found a needle, rubberband, and burnt spoon... yeah, someone was doing heroin, or crack cocaine...