THE VEHICLE WAS SITTING PARKED UNDER A CARPORT FOR ALMOST 24 HRS. WHEN IT INEXPLICABLY CAUGHT FIRE. THE ENSUING FIRE BURNED THE CARPORT AND SPREAD TO THE STRUCTURE CAUSING EXTENSIVE PROPERTY DAMAGE TO THE EXTERIOR AND INTERIOR OF THE RESIDENCE. A PASSERBY MADE THE ELDERLY OCCUPANTS OF HOME AWARE OF THE FIRE AND THEY WERE ABLE TO GET OUT. THE AREA OF FIRE ORIGIN WAS IDENTIFIED AS BEING ON THE PASSENGER SIDE OF THE ENGINE COMPARTMENT. THERE APPEARS TO BE SOME OTHER EVIDENCE AND/OR INSTANCES OF FIRES IN THESE VEHICLES OCCURRING THE SAME WAY.