AS I WAS PULLING INTO A PARKING SPACE ON THE 4TH LEVEL OF A 6 STORY PARKING BUILDING, I HAD MY FOOT ON THE BRAKE PEDAL AND THE VEHICLE WAS COMING TO A STOP, SUDDENLY THE VEHICLE ACCELERATED (LOUNGED) FORWARD. THERE WERE STEEL CABLES (RAIL GUARDS) THAT STOPPED THE VEHICLE FROM GOING OVER AND NOSE DIVING ONTO THE STREET BELOW. THE FRONT BUMPER AND THE HOOD WERE DAMAGED. I TOOK THE VEHICLE TO THE LOCAL LEXUS DEALER AND HAD THEM CHECK THE BRAKING SYSTEM FOR ANY DEFECTS. AFTER DOING A "HEALTH CHECK" ON THE VEHICLE THE LEXUS REP TOLD ME THAT THERE WAS NOTHING WRONG WITH THE BRAKING SYSTEM. I ALSO FILLED A REPORT WITH LEXUS CUSTOMER SERVICE AND THEY TOLD ME, A TECHNICAL INSPECTOR WILL GO TO THE DEALERSHIP AND CHECK THE VEHICLE OUT. *TR