i had an aftermarket power moonroof installed in my previous 1998 Intrepid ES.
I personally would not recommend it, or ever do it again.
Though, I never had any leaks, I am positive that it I had kept the car for any length of time, it was bound to happen eventually.
The roof on a car without a sunroof, is not designed to have a sunroof added by cutting a hole. The hot and cold weather of the chicago area caused the metal of the roof to expand and contract over time, causing it not to sit flush with the sunroof after less than a year. It really bothered me, and was part of the reason I got rid of that Intrepid.