It comes with clips that clip to the lip of the sunroof and to the bottom of it with a manual type screw. A little tricky but he includes (or at least for me) different size clips and tells you which one should work. I used different one than he suggested and basically stood on center console with my head/hands out the sunroof to attach. Once I got it started with the right clip, took less that ten minutes to complete.
You just have to make sure that the rubber molding on the bottom is seated correctly - not tucked under.. No issues on mine. Ran through car washes too. Really cuts down the wind noise and a lot of the heavy wind action. Price is damn good too!
Does not interfere with the operation of my sunroof too. Also have the XM or OnStar antenna and it didn't interfere with it either.