When my 2014 351 was in for one of its many warranty repairs they installed anti rattle kits from hehr I believe is brand. It made better but not to my liking. In the end I adjusted those plastic retainers where window closes in frame at top middle and bottom. Then I took a pair of pliers and bent the inner frame towards outside at those 3 points maybe an 1/8" each. Then once close widow the retainers grab the glass tight and that resolved about 98% of that pet peave! Put some cloth between the metal and pliers so not to scratch it.
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2014 Georgetown 351DS
Chevy Colorado Crew