Luckily I've never had this take place. Most months I have a rental car for 15-25 days, depending where I am. I've accidently damaged 2, one by backing into a pole, and another when a truck laid an egg.

I have been very upset with the customer service I receive somewhat regularly. I've had cars not full of gas, moldy/stained interiors, etc. I've had agents try to trick me into paying for an upgrade when they didn't have the car I reserved, same w/ GPS. Last night I was completely ignored for a good 2-3 minutes until the agents ended their conversation about their hours this week and acknowledged me. I've also had it before where the car was brand new and had no plate. It takes a lot of jumping through hoops to get a temporary airfield pass for a vehicle w/ no license plate.

Good luck with Hertz. They suck!