WHILE VEHICLE WAS IN PARK WITH A BOAT HOOKED ON BACK, IT TOOK OFF INTO REVERSE WITHOUT WARNING ,CAUSING BOAT TO COME THROUGH BACK WINDOW. ALSO, CAUSING VEHICLE TO ROLL BACKWARDS INTO WATER. DRIVER HAD TO JUMP IN CAR AND PUT THE CAR IN DRIVE TO GET CONTROL AGAIN. DEALER SAID VEHICLE WAS FUNCTIONING PROPERLY AT TIME OF INCIDENT. *AK