PARKED CAR IN PARKING LOT--BACKED INTO SPOT--PUT INTO PARK?--SHUT OFF ENGINE/REMOVED KEY AND EXITED VEHICLE/LOCKED DOOR AND WENT INTO STORE--WAS INFORMED WITHIN 5 MINUTES CAR HAD ROLLED APPROX' 50 FEET INTO FRIENDS PICKUP TRUCK..MY LEFT FRONT[DRIVER SIDE] HAD SMASHED INTO RIGHT REAR OF TRUCK-NO DAMAGE TO TRK--MY CAR ACTUALLY IN REVERSE WHEN KEY REMOVED AND ENGINE STOPPED. *TR