I was traveling South on the 405 freeway when I passed Nordhoff St when a silver Acura Integra passed by me in the carpool lane. Just at the rear of the car passed me the bumper somehow disconnected from the car which sent the car into a fish tail. I had about 100 feet, where I slammed on my brakes and the Acura veered right spinning into 180° facing oncoming traffic, he then spun 5 lanes to the right shoulder somehow avoiding the somewhat heavy traffic and flipped off the rail over onto the on ramp of Nordhoff St. Damn! I think I almost died, hopefully they driver and passenger are OK.