WHILE DRIVING APPROXIMATELY 50 TO 55 MPH, THE VEHICLE BEGAN TO GAIN SPEED ON ITS OWN. TRYING TO AVOID HITTING ANOTHER VEHICLE, THE CAR WENT INTO AND HIT AN EMBANKMENT HEAD-ON. NEITHER AIR BAG DEPLOYED, AND NONE OF THE THREE SEAT BELTS HELD PASSENGERS. DRIVER SUSTAINED FACE AND HEAD INJURIES. FRONT PASSENGER SUFFERED NECK AND SHOULDER INJURIES. BACK PASSENGER SUSTAINED HEAD INJURIES AND ABRASIONS. DEALER AND MANUFACTURER WERE NOTIFIED. *AK