My wife had a major event on the M25 in her 2004 320 CLK when it stalled/engine suddenly stopped without any warning. Jayne was in the outside lane, keeping up with traffic, so 75-80, when all of a sudden she was powerless, she managed to drift across from lane to lane with much flashing of lights and horns going off all around and very badly shaken up! An error message just advised visit workshop, after 5 minutes she restarted it and the "no malfunction" message came up, so she drove to Jct 9, staying in the inside lane and down the A24 towards home, when the same thing happened again. She contacted the excellent John Haynes who told her to bring it straight in, provided her with a courtesy car and sorted the problem within 24 hours. It turned out to be the HFM sensor which was replaced along with the air filter. Anyone heard of anything similar happening before?