Well his advise was not always correct. I drove a 1967 Buick with no back window for 8 years and when it rained, it rained in the back. Car looked like crap but it was paid for.
Whenever, I went out of town, I rented cars and always treated them with respect and never got any complaint.
So the car was a beater. Was it full of trash (cans, bottles, magazines, used paper towels)? Was it dirty on the inside and outside? Essentially, was it kept as neat as possible within the limits of the age of the vehicle or was it a trash can on wheels? Pink slips (titles) are good things.