Hold up, is this yet another case within a week that it was taken to said garage and still the problem was not found nor fixed or no one cared what actually the person was there for? Since when is it up to customers to solve their own issues...common theme here. Who told you thrust arms, why didn't they look at your DS, I mean come on wtf. This I am taking my car to a known bimmer shop yet can you guys on the forum tell me what the problem is even after being there has become a joke.
Did they not test drive it, hoist it and look for any issues? Hey maybe this isn't the full story maybe you just walked in looking for a tire balance and never mentioned why you were there and they didn't care to ask. Or maybe you did and they can't find the issue themself.
It just erks me to hear someone has an issue, visits a garage of bimmer pro's yet returns with no answers, something is not right there, very strange imo. If you returned to say they didn't find an issue but I am going back etc, fine but sounds like youre just swapping parts out till you hit it and the garage is happy to take your money while you try to find an answer yourself, not how it should work.