Originally Posted by YvesD
luckyu, could you just clarify something for us please?
You have rear bumpstop part Nr
You got things mixed up, can't blame you; this thread is giving various part numbers for different parts & cars.
In an earlier thread, a different Z4 part Nr 33 53 6 770 350
That's what I have (rear). That is bump stop plus dust tube, which you'll need because the bump stop doesn't fit the stock dust tube.
That part is used on a number of cars, don't remember exactly which. Also, there are a couple of different Z4 bump stops, this is the one I chose to use, it's been too long since I looked into all this to remember the details, but this one seems good, if you use another one you're on your own!