Mine likely to be coming from the same area. It is also very faint but I am the type that any abnormal sounds coming from my car bothers me.
Originally Posted by John NY
I also have a very, very faint rattle coming from the driver side door by the pillar where the seatbelt comes out. It's so faint that I likely won't do anything about it. I'll take it in if it gets worse, but I've not had the best of luck having the dealer try and fix rattles. When they take the car apart to fix one rattle, they almost always inadvertently create a new rattle or squeak. I had that problem with my E90.
Current - 2013 N55 535xi Msport SAT
Retired - 2009 N54 335i Msport 6MT
Retired - 2000 M52TU 323i ASA Supercharged 5MT
More photos of my car here