CONSUMER TURNED OFF ENGINE, SHIFTED GEAR IN PARK POSITION, REMOVED KEY. MINUTES LATER VEHICLE STARTED TO ROLL BACKWARDS ,DOWN A HILL, RAN INTO A PARKED TRUCK. CONSUMER HAD NOTICED THAT VEHICLE HAD JUMPED OUT OF GEAR, WENT FROM PARK POSITION TO A REVERSE POSTION.THIS DEFECT CAUSED EXTENSIVE DAMAGE AND COULD HAVE CAUSED PERSONAL INJURIES. *AK