AIRBAGS DID NOT DEPLOY IN ACCIDENT AT 40MPH DUE TO SENSOR FAILURE. DECELERATION WAS EXTREME ENOUGH TO FRACTURE MY BACK AND CAUSE CHEST INJURIES FROM STRIKING STEERING WHEEL. MINI COOPER REARENDED A SUBURBAN TRUCK THAT WAS STOPPED AT INTERSECTION CAUSING ENGINE TO BREAK LOOSE FROM MOUNTS AND HOOD TO CRUMPLE. SENSORS FOR AIRBAGS SHOULD HAVE DEPLOYED AT THE SPEED AND IMPACT.