I took it in to BMW a few weeks ago and they found a stiff joint in the drive shaft. They replaced the driveshaft (which included the flex-disc and center bearing, I was told)
We still have the same problems plus we've noticed more problems since then;
3) I was riding passenger with her and the car apparently slipped out of drive for a second. The rpm revved then it went back to normal. The shifter did not move.
4) My wife heard a short, loud scraping noise underneath the car as she was leaving work. It did this on her two days in a row at about the same time and location. It has not done it since.
I took the car back to BMW. They say they can't find anything. I've asked them to flush and change the tranny filter. They say it wouldn't make any difference and would be a waste of my money.
If I have it flushed, maybe I should take it to an independent.