The Sunseeker roof is one piece of fiberglass. It is crowned. But it does not wrap over the sides. Instead they have a separate wrap corner piece, and seam covered with a typical roof trim strip, and of course where the sides meet the front and rear seams, there is a corner that catches water. It's not optimal IMO, but I will be closely watching and maintaining those seams. I have gone back and forth about applying Eternabond tape, but for now I think I will just stick with Dicor lap sealant and keep an eye on things. I need to put some Dicor over the exposed screws!
Here is a photo of the top-side seam: