VEHICLE SITTING IN DRIVEWAY AFTER BEING USED ALL DAY. OWNER WAS ALERTED TO PROBLEM WHEN THE HORN ON THE VEHICLE STARTED BLOWING. OWNER WENT OUTSIDE OF HOME TO SEE WHY THE HORN BLOWING AND FOUND THE VEHICLE ON FIRE. CALLED FIRE DEPARTMENT. FIRE OF VEHICLE FULLY INVOLVED WHEN THE FIRE DEPARTMENT ARRIVED AND EXTINGUISHED THE FIRE. *AK