WHILE DRIVING ON THE HIGHWAY AND WE NOTICED SUDDEN SMOKE WITHIN THE CAR. THE CAR GOT VERY HOT. WE STOPPED AND OPENED THE ENGINE COMPARTMENT IN THE TRUNK AND NOTICED THAT THE INSULATION MAT IN THE ENGINE COMPARTMENT WAS ON FIRE. WE DID NOT NOTICE ANY CAUSES THAT COULD HAVE LEAD TO THE BURN BESIDES THE MAT ITSELF.