RAINING, TRAVELING NORTH, FAR RIGHT LANE ON VERY BUSY STREET IN LOS ANGELES (SEPULVEDA) WHEN A CAR TRAVELING SOUTH TURNED LEFT. WE DID HEAD-ON IMPACT INTO THE SIDE OF HIS CAR. HIS AIRBAG DEPLOYED - OURS DID NOT - BUT THE MOST CONCERN IS THAT THE FRONT PASSENGER-SIDE SEAT BELT MALFUNCTIONED THUS ALLOWING THE IMPACT TO THROW ME FORWARD AND ON THE IMPACT STRIKING MY HEAD ON WINDSHIELD OR VISOR AND BOTH KNEES AND LOWER LEGS ON DASH; THEN THROWN BACK INTO SEAT RESULTING IN WRENCHED BACK AND NECK, KNOCKING AIR OUT OF ME. THE SEAT BELT WAS LOCKED INTO AN EXTRA-LARGE POSITION WHEN CAR STOPPED. THE DRIVER-SIDE SEAT BELT HAD NO PROBLEMS AND DRIVER WAS NOT INJURED. *NM