This you can buy from BMW for about R750.
Pretty easy to replace by yourself, check on YouTube as there are a few videos on how to do it. it is very easy. I replaced it on my E92.
The old trim just gets pulled out, just work slowly as there are little channels that "clip" around the glass.
Dealerships wont replace it as they "scared the window will crack" and they wont risk it, but they talking sh!t, it wont crack, just check the video
Good luck.