VEHICLE FAILED TO MAINTAIN ITS COURSE UNDER SUDDEN STEERING CHANGES ORIGINATED TO AVOID COLLISION WITH ANOTHER VEHICLE. IT SPUN DUE TO EITHER LIGHTNESS OF THE VEHICLE OR FAILED STEERING, AND HIT THE GUARD RAILS. THE NEW 2007 TOYOTA YARIS VEHICLE HAD ONE NEW BRIDGESTONE POTENZA RE92 TIRE (DRIVER SIDE REAR) REPLACED BY THE DEALER EARLIER THAT DAY JUST BEFORE THE FAILURE OCCURRED. THE VEHICLE WAS DECLARED A TOTAL LOSS. *JB