I have the same issue but mine rattles even in the up position. Dealerships telling me they don’t know what to do, I’ve heard the real fix is getting them to replace the window regulator.
My most annoying issue is my passenger side window rattles every time I hit average bumps. I’m not talking the issue of rattling when the windows half down, this is happening with the window fully up. First, the dealership tells me they can’t replicate it, so I promptly send them 10 videos...