WITH TRUCK PARKED--IGNITION OFF-UNOCCUPIED-DRIVER WINDOW 1/2 "OPEN- AWOKE IN MORNING TO FIND ENTIRE INTERIOR OF TRUCK BURNED APPARENTLY OVERNIGHT- ARSON INVESTIGATORS DETERMINED FIRE STARTED IN DRIVERS SIDE DOOR AREA PROBABLY DUE TO RAIN ENTERING THROUGH SLIGHTLY OPEN WINDOW CAUSING POWER WINDOW ELECTRONICS TO OVER HEAT AND IGNITE. *AK