Hi, I Had the same problem. Just screwed random pin that i found at home. If you don't have spare pins, you can try to take it from PC, TV or any other thing that you will find at home (like i did LOL). Just need to find the right size. I don't think that for such a "big" problem you need to go to dealer.
Any updates on this? I am missing the pins for the first 2 panels and it is getting really annoying to have to manually adjust my sunroof every time I try to close it completely and the whistling and bouncing at highway speeds