Yeah the roof is fully closed. When I first bought the car I did clean the crevices of the sunroof (looking down from the top). Among somes leaves and an old piece of gum, I pulled out a thing made of felt, maybe? No nuts, bolts, or screws that I can see.
From the naked eye and a lot of poking around everything seems to be in place. I've never taken off the liner or unscrewed anything in the roof (probably can't put it back together in one piece)
Thanks for help you can extend!