I have shed blood and tears getting some of those interior trim panels back in place in past.
I somehow managed to make the belt retraction thing worse on mine when i pulled off the b pillar trim to replace rear quarter window seals. It is a bit annoying.
This is the part I am talking about. Looking through the pictures here, seems to suggest that little rubber/plastic seal is a part of the piece itself. I'll report back once I have my hot hands on it for real.
http://www.ecstuning.com/BMW-E36-M3-S50_3.0L/Search/SiteSearch/Cowl/ES2587342/