VEHICLE WAS PARKED IN RESIDENTIAL DRIVEWAY. DRIVER REMOVED KEY, EXITED VEHICLE AND REMOTELY APPLIED THE DOOR LOCKS. VEHICLE IMMEDIATELY BEGAN COASTING DOWN AND ULTIMATELY OFF THE DRIVEWAY, DOWN A STEEP GRADE INTO THE YARD UNTIL IT STRUCK A TREE APPROXIMATELY 50 FEET AWAY. RESULTING SIGNIFICANT DAMAGE TO FRONT OF VEHICLE WAS APPRAISED AT $5900. CAR COULD NOT BE REMOVED FROM ITS RESTING PLACE AGAINST TREE EXCEPT BY TOW TRUCK. TOW DRIVER INDICATED THAT VEHICLE WAS STILL IN DRIVE, NOT PARK WHEN HE EXTRACTED IT FROM CRASH POSITION. TOW DRIVER AND REPAIR FACILITY INDICATED THAT IT SHOULD NOT HAVE BEEN POSSIBLE TO REMOVE KEY FROM IGNITION WITHOUT VEHICLE BEING IN PARK, YET THAT WAS THE SPECIFIC CAUSE OF THE CRASH. *TR