If you go that route let me know. I am all for having them welded, sealed, whatever it takes shut to fix the problem. I havent seen a solution to this problem yet.

 

I have a 1998 D1 with a badly leaking rear sunroof, and fixed it with a couple of simple steps. First, check the drain tubes. I bought a 100' roll of semi rigid 1/8" drip irrigation tubing for $3 and cut off a length about 8' long. Open the sunroof. There are two drains in the sunroof drain pan, one on each side of the pan at the end closest to the rear passenger seat.

The drain tubes connect to the pan and exit in the rear wheel wells (front side). I gently pushed the length of 1/8" tubing into each drain tube from underneath the car, and fed it through the tube until it reached the drain pan. I was able to determine that the drain tubes were clear.

I removed the rear E-pillars and skylight trim on both sides, then dropped the rear of the headliner about 3", which allowed me to inspect the drain pan. I closed the sunroof and had a helper slowly pour some water around the edge of the sunroof while I watched the drain pan from inside the car. I found water seeping in around several of the machine screws holding the pan to the roof, and bad leaks around a couple of small square holes in the pan that plastic guides for the sunroof mechanism snap into from above.

I dropped the headliner another couple of inches and removed all of the drain pain screws, which allowed me to lower the pan a couple of inches without having to pull the sunroof motor.

I ran a 1/8" bead of black silicone around the top edge of the drain pan and reseated it. As I replaced each machine screw, I add a tiny bead around each screw just under the head to help seal it. The little square holes for the mechanism clips were also silicone. Finally, I ran a tiny bead of black silicone around the edge of the sunroof frame on top. If you're careful, it won't be visible.

After checking for leaks and finding none, I refitted the headliner and trim. Several rainstorms and a couple of carwashes later, and my sunroof is dry as a bone.

 

Great write up. My first question is: Are your sunroofs still functioning or sealed shut forever?

Problem I'm facing is my sunroofs won't even open. My rear one can be opened about an inch if you lift the glass from the roof with your finger. Otherwise, push button to open and nothing happens. My goal whenever I can get around to it is to seal the sunroofs completely. I'm all for removing the tray and everything and just having a glass window if that's even possible. What I wouldn't give for the SD version of mine.