I WAS IN MY DRIVEWAY, STOPPED, GETTING READY TO PULL IN TO THE GARAGE. I HAD STOPPED WITH MY FOOT ON THE BRAKE PEDAL, AND THEN I PRESSED THE BUTTON TO OPEN THE GARAGE DOOR AND WAITED FOR THE GARAGE DOOR TO GO UP. WHILE THE GARAGE DOOR WAS STARTING TO GO UP AND THE BRAKE PEDAL WAS STILL PRESSED, THE CAR SUDDENLY, UNINTENTIONALLY, UNEXPECTEDLY ACCELERATED BY ITSELF INTO THE GARAGE DOOR CAUSING THE WINDSHIELD TO BREAK ON THE GARAGE DOOR AND THE GARAGE DOOR TO BREAK OFF OF ITS TRACKS. IT IS UNKNOWN THE COMPONENT OR SYSTEM THAT CAUSED THE SUDDEN UNEXPECTED ACCELERATION. IT COULD HAVE BEEN THE ENGINE, FUEL/PROPULSION SYSTEM, OR SPEED CONTROL. BUT SOMETHING CAUSED A SUDDEN UNEXPECTED ACCELERATION WHILE THE BRAKE PEDAL WAS APPLIED.