If ever there was something that would scare you about renting a car, it’s recurring stories about rental car companies billing people for repairs for damages they swear they didn’t do -- months after they turned the car in. How do you prove a negative, that that ding in the door didn’t exist when you turned the car in? And how do you protect yourself when no employee of the rental agency is available to do a walk-around inspection with you? The stories seem to be cropping up more frequently -- along with accusations that rental car companies have found a questionable new source of revenue. Read this story by Christopher Elliott, consumer advocate and author of the syndicated Travel Troubleshooter column, and like me, you’ll be shooting photos of every tiny ding and scratch on a rental car before you even open the door. Just make sure that the time stamp on your camera is correct.