Plastic loose under the hatch wing
 

How do I tighten? Seems to rattle with the bass. Thanks

there should be clips. I don't think there's anyway to get around that.

shove some material in there so theres no more room to rattle :)

Some weatherstrip or something. Home depot has loads of it.

Well, I put some foam weatherstrip along the very back of the piece and while there are still some rattles, they are significantly reduced. Thanks!

Spoke too soon, seems to be the same amount before the weatherstrip. I believe it's actually coming from the front of that trim piece (when you're in the car, all the way in the back). How is that attached as I want to try some weatherstrip over in that area? Thanks!