Is this the sound you are hearing? If so this was a issue on the F80s. The dealer installed the tape you see in the following video and it helped but the noise came back but it wasn't as loud. I started to apply Nextzett Gummipflege Stift to that area and the nosie went away.
Nosie
https://youtu.be/hKP1WkCYcgA
Solution
https://youtu.be/gLs1ycPjZMw