I had a aftermarket done years ago. It was simple, just opened in the back. I never leaked. Don't recall the brand.
Webasto 700 is the one installed from what I have seen online. Only concern is safety once they ripped a hole in the roof and overtime structurally how it will be with leaks. Top Coverage| Autmotive Accessories| Leather| Sunroofs| Illinois
You don't really need one. But on the right day it's a OK substitute for the convertible I don't have.