Gdwheel

I can't help with a solution, but have a similar rattle. I have not had my dealer look at it. I forgot about it when I had it in for service.

I have none of these issues with my 2015i Tahoe LTZ. Perhaps I just don't notice, but I have had many people (wife, kids, others) ride with me too and no one has had any complaints. Maybe I got lucky. My only issues have been lift gate struts and the rear window trim about fell off on both sides.

Just to change things up a bit, 8 months and 6500 miles on my 2015 Tahoe LTZ, including three very long trips, and no issues. Not one problem (knock on wood). I love it!