Z4-forum.com

I had this problem last winter, it turned out to be the thumb wheel.

I did RTFM but it is far from clear. I even checked it into the dealers under warranty and they didn't spot the problem!!! I eventually stumbled across the solution almost by accident, I felt pretty stupid but then BMW didn't seem to know either.

That's very interesting. I'm still wary of mine and I'm going to have a chat to the service department again .