On the whole, we had great experiences with dozens of car rentals. We usually reserve lower priced cars, and many times we were given free upgrades because what we had reserved was no longer available. Here are some of the few mishaps we did have:
-- We recently returned a Hertz rental car, and I made sure to obtain in writing that we returned it undamaged and with a full tank. Then there was a $80 funny charge on our credit card. Calling, I was told it was for filling up the car. When I stated I have in writing that we returned the car with a full tank, then they quickly reversed the charge.
-- Somewhere, having driven only 10 miles, the gas tank was already 1/4 empty, LOL.
-- Likewise, we had reserved an AVIS car and were given a car where the driver's door didn't open. After some haggling, they gave us a better car.
-- At one airport our reserved car was unavailable, so they wanted to give us a limo. No way, uses too much gas and difficult to park. After some arguing, we got a perfect deal,
-- We carry only 3rd party insurance at home and are self-insured for the rest that usually would cover rental cars. I only had once a minor accident with a rental car, so VISA paid for the damage to the rental car.
-- When we once returned a mobile home, another family was crying. Their travel agent had told them to rent a mobile home upon arrival, but none was available. I felt sorry for them because their dream vacation was in ruins.
-- Perhaps I don't remember everything. But for sure, we never had a really bad experience.