I STARTED THE CAR IN A DRIVEWAY, INTENDING TO BACK ONTO THE STREET. WHEN I PLACED THE CAR IN REVERSE, THE CAR ACCELERATED BACKWARD AT TOP SPEED. I COULD NOT STOP THE CAR BY APPLYING THE BRAKES. I HAD 40 FEET OF SKID MARKS VISIBLE ON THE PAVEMENT. THE CAR WAS STOPPED BY IT'S IMPACT WITH A PARKED CAR. I HAVE BEEN TOLD THAT THIS TYPE OF INCIDENT HAS HAPPENED MANY TIMES WITH 1986 AUDI 5000 MODELS. WHAT SHOULD I DO WITH THIS CAR? IS IT SAFE TO CONTINUE TO USE?