My 2018 GTS has recently starting rattling at the back of the sunroof headliner. I have held the back of it while driving and that seems to be the culprit. I have pushed felt along where I could get my fingers in but not sure that helps because it is farther inside of it. Not a real handy guy and not sure if it just pulls off and do not really want to break it. Any thoughts or solutions in what I could stuff inside so there is no give or movement. Trying to nail this down, it seems it is just behind the passengers head on the headliner. Thank you in advance.

 

I think there have been some threads over this already, those members should respond to you. I wouldn't fool with it, take to the dealer as you're under warranty.

Left off the sunroof when I ordered mine, I've had sunroof issues before like leaks, rattles, etc.