I have a 2010 Escalade with 150k on it and I wanted to share my experience with a driver side B pillar rattle that would not go away. It appeared about a year ago and because it sounded like it was right next to my ear it was driving me crazy. I took apart the B pillar cover and checked over the seat belt mechanism to make sure everything was tight....still rattled. I had read on some other forums that the problem was caused by the rubbers in the back door rubbing and was the cause. The fix was to tape a towel in place so it was between the door frame and the rubber when it was closed....still rattled. I began to think maybe it was the drivers door latch becoming worn and there was some micromovement in the door itself...wrong. Finally fed I talked to a knowledgeable GM mechanic who took the truck for a ride and knew right away what the problem was. He replaced the power window regulator and the problem was solved 100%. Based on where the noise seemed to be coming from I would have never figured it out....hope this helps someone being driven crazy with the same rattle.