Recently my November 2008 320i ES suffered engine warning light illumination, juddering as if the car was driving on a corrugated surface, and loss of power. I was on an A road at the time so fortunately was able to get to the hard shoulder without an accident.
BMW Assistance directed me to a nearby Main Dealer. They downloaded new software, and replaced one injector and coil, but warned that the other three cylinders were vulnerable. What happens if the next one goes on the M5?