WHILE DRIVING IN MASSACHUSETTS ON 495N AT ABOUT 5:30PM I SMELLED SOMETHING BURNING. CHECKED MY GAUGES AND ALL SEEMED WELL, THOUGHT IT MAY BE A WOOD BURNING STOVE IN THE AREA I JUST KEPT DRIVING. I TURNED OFF RT495 AND ONTO RT 119. ABOUT A MILE DOWN RT119 I NOTICED A LOT OF SMOKE BUILDING UP INSIDE THE CAR, I THEN REALIZED MY CAR WAS ON FIRE AND BEFORE I CAN PULL OFF THE ROAD THE INSIDE OF THE CAR FILLED WITH SMOKE AND BURNED MY EYES AND I WAS CHOKING A LOT. I SLAMMED IT INTO PARK, SHUT THE KEY AND JUMPED OUT THE CAR. A CAR BEHIND ME PULLED OVER AND SAID HE WAS FOLLOWING ME AND SMELLED MY CAR BURNING AND TRIED TO SIGNAL ME. LITTLETON, MA FIRE AND POLICE ARRIVED SHORTLY AFTER. FIRE DEPARTMENT DISCONNECTED MY BATTERY IN THE TRUNK AND OPENED THE HOOD TO LOOK FOR FLAMES. NOT SEEING FLAMES THEY DID SEE HEAVY SMOKE AND SMELLED SOMETHING BURNING. SHORTLY AFTER THAT MY CAR WAS TAKEN AWAY ON A TOW TRUCK TO BMW IN NASHUA, NH. BMW DETERMINED THAT A FAULTY/FAILED ELECTRO MECHANICAL THERMOSTAT HAS CAUSED THE FIRE AND THE DAMAGE ESTIMATED SO FAR TO BE ABOUT $4,000.00 THEY TOLD ME THIS IS A PROBLEM SEEN BEFORE AND THEY HAD NO SUGGESTIONS AS TO WHY THIS HAPPENED BUT DID SAY IT COULD HAPPEN AGAIN! WHILE MY INSURANCE COMPANY (COMMERCE INSURANCE) REFUSES TO MAKE ANY PAYMENTS FOR DAMAGES, THEY CLAIM IT WAS CAUSED BY A FAULTY PART AND THAT BMW IS RESPONSIBLE. BMW TELLS ME THAT MY CAR IS OUT OF WARRANTY AND THIS PART IS JUST A FAILED PART. I THINK WE ARE DEALING WITH SOMETHING