THE ELECTRICAL HEATING OF THE LEATHER COVERED SEATS WAS BEING USED DUE TO COLD WINTER CLIMATE. THE PASSENGER WAS DROPPED OFF BUT THE SEAT HEATING WAS LEFT IN THE ON POSITION. WHILE DRIVING DOWN THE ROAD, A BURNING ODOR WAS NOTICED, THEN SPARKS AND THE LEATHER COVER AND PADDING IGNITED. WHILE STOPPING THE VEHICLE TO EXTINGUISH THE FLAMES, A HOLE THE SIZE OF A QUARTER WAS BURNED INTO THE SEAT BACK.THE BURN HOLE EXISTS IN THE MIDDLE OF THE SEAT BACK IN THE THREADED SEAM. SMOKE DAMAGE EXISTS ON THE UPPER PORTION OF THE SEAT BACK. THE HEATED SEAT HAS STOPPED WORKING. *AK