Hey y'all. Tomorrow will be a month since I bought my Denali XL. I average 1400 (mostly highway) miles a month. I recently noticed a couple weeks ago while driving low speeds through my neighborhood. There's a rattling/squeak coming from the very back when I go over small "ripple" type road surfaces. It sounds like it's coming from the back glass. I don't have anything in the back, and I tightened all the torx bolts under the "spoiler" that are accessible when you open the rear glass...no luck. It's funny, years ago, I bought a 1989 S-10 Blazer w/160k miles as a work truck/DD and it made the same rattling noise from the rear glass. Anyone else having the same issue? Is the rattle coming from somewhere else?