This is a follow up to an earlier article about the polycarbonate roof. It contains one additional piece of information, namely that the roof panel is silicone hard-coated. It looks as if this is some kind of scratch resistant finish that is added to the polycarbonate:
http://www.openpr.com/news/31312/Lar...rtwo-roof.html
I was a little concerned about how the panoramic roof would stand up to daily wear and tear, since clear plastics tend to scratch easily and can end up looking pretty ratty after a while. Hopefully the hard-coating process will reduce that problem.