WHILE DRIVING OUR 2002 MAZDA TRIBUTE ON THE HIGHWAY, A FIRE STARTED UNDER THE CAR - WE SUDDENLY NOTICED ENGINE STARTED TO STUTTER AND THEN SAW SMOKE COMING OUT OF THE BACK OF THE CAR AND THEN THE EXHAUST PIPE FELL OUT OF THE REAR. WITHIN A MINUTE OR SO AS WE WERE TRYING TO PULL OVER, BOTH THE STEERING WHEEL AND THE BRAKE FAILED. WE FINALLY BROUGHT THE CAR TO STOP ON THE SHOULDER OF THE EXIT RAMP CLOSE BY, BY DECELERATING AND USING THE PARKING BRAKE. WHEN WE GOT OUT, WE SAW ACTIVE FIRE UNDER THE CAR TOWARD THE BACK. THE FIRE WAS PUT OUT ALMOST IMMEDIATELY BY A PERSON WHO STOPPED TO HELP US WITH A FIRE EXTINGUISHER. ALL OF THIS TOOK LESS THAN 5 MINUTES. THE FIRE MEN WHO ARRIVED AT THE SCENE WITHIN MINUTES OPENED UP THE HOOD AND SAID THERE WAS NO ENGINE OIL. THE POLICE WAS PRESENT AT THE SCENE. THE CAR WAS PURCHASED NEW 4 YEARS AGO AND WE'VE HAD NO MAJOR PROBLEMS FOR THE LAST 55,000 MILES. THE ENGINE OIL WAS FILLED 5 DAYS BEFORE THAT AND THE CAR RAN FINE FOR THE 450 MILE TRIP RIGHT UP TO THAT POINT. THE LOW ENGINE OIL WARNING LIGHT DID NOT COME ON UNTIL AFTER THE VEHICLE CAME TO A STOP. AAA ADJUSTER SUSPECTED AN ENGINE PROBLEM AND HIS THEORY WAS THAT ENGINE SHAFT BROKE AND PUNCTURED THE OIL PAN FROM INSIDE BUT NO FORENSIC INSPECTION WAS CARRIED OUT BY THE INSURANCE COMPANY. THE CAR WAS TOWED TO A MAZDA DEALER SHOP FOR INSPECTION AT OUR REQUEST BUT THE DEALERSHIP REFUSED TO OFFER A CONCLUSIVE EXPLANATION OR CARRY OUT A FORENSIC INSPECTION. THE CAR IS CURRENTLY PARKED