CAR SITTING PARKED ON 70F DAY FOR 4 HOURS. IT HAD BEEN DRIVEN FOR ABOUT 25 MINUTES BEFORE THAT AT 60-65MPH. I WENT TO OPEN THE CAR DOOR AND NOTICED THAT THE TRUNK WAS UNLOCKING REPEATEDLY. OPENED THE CAR DOOR AND WATCHED SMOKE POUR OUT. ENTIRE LEFT-HAND SIDE OF THE FRONT PASSENGER SEAT HAD BURNED AND THE RIGHT-HAND SIDE OF THE CENTER ARMREST HAD MELTED. THE HEADLINER HAD BEEN BURNED ON THE RIGHT-HAND SIDE OF THE CAR AS WELL. THE DOORS AND TRUNK CONTINUED TO LOCK AND UNLOCK UNTIL WE HAD GOTTEN THE FIRE OUT AND FINALLY GOTTEN THE BATTERY DISCONNECTED. BURNT DEBRIS SCATTERED THROUGHOUT CAR WHERE LIT MATERIAL FLOATED AROUND AND FINALLY FELL BACK TO THE SEATS/FLOORBOARD. WINDOWS WERE NEARLY BLACKED OUT BY THE SMOKE. *TR