I have something similar on the left side as the bolsters tighten it makes this absolutely terrible ear scratching sound. Much worse than whats on the video.
I'm afraid this indicates a brand new seat. There is no way to open them up and fix them because of the way these M5 seats are. Changing seat in this car is also not easy, both doors have to be removed
It looks like there are more bugs with this car than there were with Windows XP