WHILE DRIVING AT 50 MPH HEARD A MUFFLED POP LOOKED OUT DRIVER SIDE VIEW MIRROR TO SEE FLAMES SHOOTING OUT LEFT REAR OF CAR. TURNED AROUND TO SEE ENTIRE REAR OF CAR ENGULFED IN FLAMES. PULLED OVER, FLAMES AT REAR TIRE, GOT FAMILY OUT AND IN 5 MINUTES ENTIRE CAR WAS TOTALLY ENGULFED IN FLAMES. HAVE CONTACTED GM WHO REFUSED TO GIVE ME ANY IDEA OF WHAT A PROBLEM CAUSE WAS. HELP. *AK