I bought a '15 Yukon XL SLT about a month ago. I've had a rattling noise from both the drivers' and passengers' side seat belt housing and I was searching the internet for info if others were having the same problem. Turns out a few do, as well as the 2nd row captains chairs rattle like a 1970's pickup truck when going over medium size bumps in the road. And the pressure buffetting, I thought maybe that was just me but my truck definitely has this problem, though I haven't been able to pinpoint when and why it does it. It feels like one window is open, but then it will go away. And it is not consistent. I do not have a sunroof.
Driving to work this morning with a rattling in my ear and the rear seats rattling over every bump, I was getting very frustrated.