Well, I am glad to know that I am not alone. Just got my M back from dealer after a month. It had been there for a week and half. They were getting turbo malfunction error codes from ecu. Took apart turbos, "tuned them" and returned the car. 45 miles from dealer and there came the warnings again. 6 different sets in 115 miles. Car flat beaded back to dealer. Had it 2.5 weeks more and just got it back. 200 miles and no issues yet. Have already informed BMW that if third time occurs, car is theirs. I am happy to take replacement or new vehicle (5er), but will not take mine back. They still don't have a real idea as to what was wrong. Replaced all "hoses" to turbos and reassembled them is what I am told. Had regional rep in to review the vehicle and inspect repairs.

J