I've got something up there that must be loose becuase when I push up gently on the plastic cover it goes away. How can I take the cover off to get in there an tighten it up. Front or back?

I went to the hardware store and got a small strip of felt fabric and gently tapped it to all area's that are in contact with the plastic housing. Havn't had that rattling every again!

Taking the cover off is easy, there are four metal clips that hold it on via the side. The easiest way to pop it off, is get a small flathead screwdriver and gently slide it into the edge of the housing, than move it all around the edge. Eventially it will unhook all the clips and the housing should pop off.

check to make sure there's a hex key (4mm, if I remember correctly) in the clips on the inside of the cover. I'ts for manually cranking the sunroof closed in an emergency, and naturally my emergency included pouring rain and the hex key wasn't there!

I have the same problem... Rattle comes and goes. Pressing up on the sliding cover stops it, or sometimes pressing on the roof just behind the sunroof also stops it.

I will try your suggestion -- hope it works!!!