Parking brake disengaged on 3 occasions: Button popped off parking brake handle, as if shot from a gun, and car rolled backward. 1st instance was prior to August 2012 but no damage because I was still in the car and stopped it. 2nd instance in Aug. 2012 car rolled backward into another vehicle in a parking lot, resulting in damage to my rear bumper and extensive damage to other vehicle, which was parked. 3rd instance on 5/11/13, car rolled backward down driveway. I tried to get in the car to stop it, but was not able to stop it until the driver door was caught and ripped past its normal maximum opening, extensively damaged. In Aug. 2012 after the 2nd incident, the emergency brake was checked by Audi dealer, who said they could glue the button back on but reported nothing wrong with the parking brake apparatus. Rear brakes were replaced as they were worn and dealer said the parking brake engaged the rear brakes and the worn brakes could have caused the failure. Car has received all required maintenance from the same Audi dealer. I am sole owner of car. After 5/9/13 incident, dealer refused to acknowledge any known defect, denied responsibility for damage, did not offer any sort of compensation for damage to vehicle(s) or to repair brake.

- Memphis, TN, USA