Short update:
I brought my car to the local BMW Dealer today and gave them a detailed list of the symptoms.
Unfortunately my car has another problem: There are two different clacking noises from the rear... One is metallic, the other sounds more like a heavy plastic part romping in the trunk.
I hope they are able to eliminate these flaws. I love that car but I can´t live with these noises and the strong play in the drive train...
