uh oh, this might be becoming an issue.
I had the same thing happen to mine, but mine is just a normal SE hatch without a moonroof. I got in my car one day (I can't remember if it just rained or not), and for some reason I looked up, and thats when I saw a stain by the map light, then I checked the whole interior and found a big yellowish stain was surrounding the hanger hook by the passenger side, and spots here and there by the back LED light. At first I thought one of my friends mightve done something, so I tried cleaning it but it didn't do anything.
I took it in to my dealer, they tried cleaning it but couldn't get it out either, so they replaced the whole top liner with a new one about a week later. I'm worried though, because they said they tried to see if there were any leaks before they put the new one on by covering it in water for a few minutes, and even took off those long plastic pieces on the top of the roof and did the same thing, and they couldn't find anything wrong or any leakage.
They said they had never seen anything like that before, so yeah... I check everyday when I get in the car now tho, since it's been raining pretty frequently lately.
I had no idea anyone else had had the same problem, I chalked it up to being an early adopter and getting a slightly out-of-spec model. Looks like we're all going to have to watch it, and you should take it in to get it replaced, it took my dealer about 4 hours.