I wanted to do a follow-up to my previous post. I took my truck to my preferred local dealer (Rick Hendrick Chevrolet) and they replaced the driver's outside mirror. It is MUCH better! The new mirror is 100% tight and does not rattle like the old one did. The mirror glass itself is still shaky in both mirrors, but the rattle was the big issue for me and it's fixed. Thank you Rick Hendrick Chevrolet and thanks GM for standing behind your product.