IN PARKING GARAGE, TURNING INTO PARKING SPOT. CAR ENGINE REVVED UP, AND CAR ACCELERATED INTO THE GUARD RAIL, SMASHING THE FRONTEND OF THE VEHICLE AND DAMAGING THE RADIATOR. DRIVER DID NOT PUT FOOT ON THE GAS; CAR LUNGED FORWARD ON IT'S OWN. THE AIRBAG DEPLOYED, AND DRIVER HAD DARK BRUISES ON ABDOMEN, LEFT ANTERIOR THIGH, AND LEFT SIDE OF NECK D/T SEAT BELT, AND ALSO HAD MINOR WHIPLASH. FORTUNATELY, NO OTHER CARS OR PEOPLE WERE AROUND WHEN CAR ACCELERATED. ALSO, HAD THE CAR HAD MORE THAN JUST A FEW FEET TO RUN INTO SOMETHING, THE DRIVER WOULD HAVE BEEN INJURED WORSE. PRIOR TO INCIDENT, CAR ENGINE REVVED UP FOR SEVERAL SECONDS ON ITS OWN TWICE WHILE DRIVING DOWN THE HIGHWAY.