I found a tire in the trunk of a rental car one time. I sold it to help pay to fill the car up with gas before I returned it.
Dang. Hadn’t thought of that. LOL! But a co-worker and I rented a car one time in NJ that was soooooooo bad he wanted to leave a “present” under the spare tire. May not have been noticeable until summer though. Stankyeeeeee!