ON SATURDAY, OCTOBER 13, 2018, I WAS IN A PARKING STRUCTURE LOOKING FOR A PLACE TO PARK. I WAS ON THE RAMP TO THE 2ND FLOOR WHEN FOR NO APPARENT REASON, MY CAR ACCELERATED AND HIT THE VEHICLE IN FRONT OF ME AND MY VEHICLE IMMEDIATELY QUICKLY REVERSED BACKWARDS AND HIT THE VEHICLE BEHIND ME. THE VEHICLE CONTINUED TO MOVE BACK AND FORTH LIKE A BUMPER CAR. I WAS TRYING TO PRESS THE BREAK BUT NOTHING HAPPENED. I STARTED SCREAMING FOR SOMEONE TO HELP THAT THE VEHICLE WAS OUT OF CONTROL. AFTER GOING BACK AND FORTH ABOUT 5 TIMES BEFORE BEING STOPPED BY THE VEHICLE BEHIND ME. THE VEHICLE WAS STATIONARY WHEN THIS ALL HAPPENED.