My Scion tC's panoramic roof rattles like crazy? Whats the deal?

I have a 2007 Scion tC with about 10k miles on it, and the rattling coming from my panoramic roof is progressively getting worse. I already despised the cheap plastic cover for it, and now the rattling is getting to be extremely annoying. Does anyone else have this issue? I like my tC, but I will be trading it in for an Infiniti M35 Sport soon.