I picked up a black Dodge Caliber from Enterprise at PHL in late July. Did a "walk around" with the employee at 11 p.m. in a dark parking lot. The car was dirty and scratches and dents were noted. This was not a new car as it had 19, 000+ miles on it.
Upon retun, the employee noted a "new" scratch on the bottom of the rear quarter panel. It was a small surface scratch. New? Who knows.
He put a $500 charge on my credit card and referred me to their "damage recovery unit". I have put the amount of this charge in dispute with my credit card company and will never deal with these scammers again. I'm sure a certain percentage of people don't fight claims like this and it's a windfall for Enterprise.

This is a pattern, I had a similar episode. Fortunately they did not have my credit card number and I am still fighting it.