I had the b-pillar rattle. I fixed it last weekend! You have to take both the upper and lower b-pillar trim off and you'll find it's caused by a 3 inch long metal rod that puts slight tension on the seatbelt. I put some anti-creak tape around it and it seems fine now.
Also, the buckle had slight play in it so I put some anti-creak under that too.
Seem to have another buzzing rattle now coming from the top of the dash area. Seems like its coming from the centre vent where the Bose system is fitted.
Any idea how it clips out?