AS I WAS PREPARING TO PARK AT MY LOCAL GROCERY STORE IN AN ASSIGNED SPACE I EXPERIENCED A SUDDEN UNINTENDED ACCELERATION. THE FRONT END SLAMMED INTO A CONCRETE RETAINING WALL, CAUSING MAJOR DAMAGE TO BOTH MY VEHICLE AND THE RETAINING WALL. THE CAR WAS PRACTICALLY AT A COMPLETE STOP WHEN THIS OCCURRED. ADDITIONALLY WHEN I REVERSED THE CAR IT ACCELERATED BACK AT A RAPID SPEED. IT WAS VERY SCARY AND THANKFULLY NOBODY WAS INJURED OR WORSE. THIS COULD HAVE BEEN A SERIOUS OR FATAL SITUATION AND I FEEL THAT THERE WAS SOME KIND OF ELECTRONIC FAILURE. CONSIDERING THE SAFETY RECORD ON THIS CAR I FELT VERY UNSAFE AND NOT IN CONTROL.