WHEN GAS PEDAL WAS TAPPED TO PULL UP INTO A PARKING SPACE VEHICLE ACCELERATED AT A HIGH SPEED. WHEN THIS OCCURRED BRAKE PEDAL WAS DEPRESSED TO SLOW AND STOP THE VEHICLE, BUT IT LOCKED UP AND FAILED. THIS RESULTED IN VEHICLE GOING OVER AN EMBANKMENT, DOWN A 5 FOOT HILL, AND CRASHING INTO A TREE. PRIOR TO THIS INCIDENT, TWICE WHEN MAKING A RIGHT TURN THE BRAKES LOCKED UP. DEALERSHIP CLAIMED THEY COULDN'T FIND ANYTHING WRONG WITHTHE VEHICLE. *AK *NM