I've seen S13 SE sunroofs with the same concept. I don't know what you have. Is yours a stock moonroof? My boy has an S13 that has the roof slide back.

 

naa mine doesnt slide back ('89) its the stock pop up moon roof

 

i didn't do the drain test, but i did try to cut around the opening today, it seems to be sealed along the inside of the car where the rubber thing is at. Is it safe to cut or will i have to silicone it again to prevent leaking. Like if i cut right along the top of the rubber thing where it meets the moon roof

 

OK I found out that only S13 coupes can do the drain test. S13 cps have slide back roofs. S13 fastbacks have to find a way to replace the seal or if you go through dealer you have to buy the whole glass which is pricey. As I get more ideas from S13 owners I'll post.