I used to park cars for Hertz at RDU airport, all the stuff we find get put in a locked drop box, phones, ID cards, tools, garage openers, keys, etc.
One time a customer complained somebody stole his video camera back in 1996, we could not find it, management searched our personal cars on the way home that day. Most of us believed that a professional thief grabbed his camera bag when he was not watching it.
Few rentals came back with damaged sunroofs, gun shot blasts, for some reason they liked renting the Volvo models.
One new parking lot attendant drove out with a 1998 new Mustang, they found it a week later with bullet holes and the guy was in the hospital. His mother came for his pay check and they had to give it to her. He was prosecuted for the auto theft.
One time a young couple were having a heated argument, the girl was knockout gorgeous, the guy a bit sketchy, she left the rental agreement somewhere, he wanted to return the car, I thought he was going to hit her, I wrote the unit number down for him and just go to the counter, he pulled out a roll of cash to choke a horse with, wanted to give me a $50, I declined, he had a revolver in his waistband. They did not fly up here. Drug runners.
I rented a car one time and there was a steak knife in the glove box, same type you would find at Golden Corral.