I am trying to sell my car and an interested party wanted an auto shop to check out the car. I brought the car to the auto shop, and dropped it off without signing any papers. They had talked to the potential buyer and knew what they needed to do (check the engine and do a walk-around with the potential buyer). When I picked up the car later that day, there was a dent that was not there before (estimated $900 in damages). I have talked to the owner and he says that he does not believe that any of his employees caused the damage and therefore says that he does not know whether or not he will help pay for the damages. Any help?