MY LEXUS LS460 SPONTANEOUSLY STARTED ON FIRE IN A PUBLIC PARKING LOT. NO WARNING LIGHTS ,NO KNOWN CAR PROBLEMS. I HAD PARKED MY CAR TO RUN INTO A STORE. WHEN I TURNED IT OFF IT MADE A LOUD REPETITIVE CLACKING SOUND. I TURNED IT BACK ON AND TURNED IT OFF AGAIN. SAME THING. I TURNED IT BACK ON AND TRIED TO BACK UP BUT IT STALLED. STARTED TO SMELL... SOMETHING WAS BURNING AND SMOKE WAS COMING FROM THE ENGINE UNDER THE HOOD. BECAME VERY CLEAR THAT THE ENGINE WAS ON FIRE. I CALLED 911 AND THE FIRE DEPARTMENT RESPONDED. AFTERWARDS, I ASKED THEM IF THEY COULD TELL HOW IT STARTED ...THEY SAID NO BUT IT WAS ELECTRICAL. I WILL HAVE A REPORT FROM THE FIRE DEPARTMENT IN A WEEK.