OTHER DRIVER SLAMMED INTO REAR OF MY CAR AT ABOUT 30 MPH. I RECALL GOING FORWARD INSIDE MY CAR BUT IT SEEMS SEAT BELT DID NOT TIGHTEN. TURNS OUT MY DRIVER'S SEAT FRAME WAS BROKEN IN THE ACCIDENT AND MY BEST GUESS IS ENTIRE DRIVER'S SEAT WAS GOING FORWARD. DON'T KNOW IF THIS IS USUAL OR NOT. I'VE NOT HEARD OF IT. ALSO, WOULD LIKE TO KNOW WHETHER THE FACT THAT THE ENTIRE DRIVER'S SEAT WAS MOVING FORWARD IS REASON SEAT BELT DID NOT TIGHTEN. *TR