CAR INVOLVED IN A LOW SPEED (20-25MPH) COLLISION. FRONT LEFT QUARTER PANEL ENGAGED REAR RIGHT OF PICKUP BED. NO HOOD DAMAGE OCCURED, MINOR BUMPER DAMAGE BUT EXTENSIVE DAMAGE TO FRONT LEFT AXLE ASSEMBLE WHEN IT WAS BROKE LOOSE FROM MOUNTINGS. AIR BAG DEPLOYED ON DRIVERS SIDE. THE DRIVERS SIDE SEATBELT FAILED TO ANCHOR ON HARD BRAKE OR ON IMPACT CAUSING THE DRIVER TO BE FLUNG FORWARD INJURING THE DRIVERS LEFT SHOULDER AND CAUSING THE DRIVERS HAND TO HIT THE WINDSHIELD HARD ENOUGH TO BREAK THE WINDSHIELD. IT IS UNCLEAR WEATHER THE AIR BAG DEPLOYMENT CAUSED THE ARM TO HIT THE WINDSHIELD. SEATBELT JAMED IN EXTENDED POSITION RAISING CONCERN BY THE BODY REPAIR SHOP AND REPLACEMENT OF THE ENTIRE SEATBELT UNIT. FURTURE THE BODY REPAIR SHOP SAID THAT THE "BURN RING" WAS NOT BURNT INDICATING THE FORCE RETRACT NEVER ENGAGED UPON AIR BAG DEPLOYMENT AND SEATBELT WAS NOT EVER RETRACTED AFTER THE ACCIEDENT -- MEANING THE WAY IT WAS EXTENDED IS THE WAY IT WAS AT THE TIME THE AIR BAG DEPLOYED. BODY REPAIR SHOP HAS BEEN INSTRUCTED TO RETURN THE BROKED SEATBELT ASSEMBLE TO ME UP ON COMPLETION OF THE REPAIRS TO THE CAR.