TL*THE CONTACT OWNS A 2006 LEXUS GX470. WHILE THE VEHICLE WAS PARKED THE VEHICLE BEGAN TO ROLL BACKWARDS. THE DRIVERS SIDE DOOR WAS OPEN AND WAS DAMAGED WHEN IT CRASHED INTO ANOTHER VEHICLE. THE CONTACT STEPPED ON THE BRAKE PEDAL AND WAS ABLE TO STOP THE VEHICLE. THE CONTACT STATED THE CENTER DIFFERENTIAL LIGHT HAD ILLUMINATED ON THE INSTRUMENT PANEL. THE VEHICLE WAS TOWED TO THE DEALER. THE VEHICLE ROLLED BACKWARDS TWICE WHEN IT WAS REMOVED FROM THE TOW TRUCK. THE TECHNICIANS WERE UNABLE TO DIAGNOSE THE FAILURE. THE VEHICLE WAS NOT REPAIRED. THE APPROXIMATE FAILURE MILEAGE WAS 44,800.