D2 sunroof leak, how to seal. (searches used!)

Ive done the search bit and read the various posts regarding headlining removal and drain tube repair etc.
My 2001 D2 has I assume leaking sunroofs, we dont get drips out the handle as some describe and the headlining doesnt seem to be wet, however after rain when you drive the can you hear water runiing above your head and we ge some coming out the top front seat belt appatures, also a drip somewhere at the rear.
I dont really want to go to the effort of removing the headlining etc.
In 6 years of owning it ive never used either sunroof, I took the handle off the back one 5 years ago as I discovered it didnt open and close very well anyway, so once I had it closed properly I removed the handle to stop anyone opening it.
As I intend to keep the car and continue never using the sunroofs, my question is this.
Can I seal them up permanantly from the outside, I was thinking along the lines of a silicone sealant, has anyone done this ? did it work ? and if so where did you seal, the joint where the glass would open, the outer joint sunroof to roof metal or both ?
Regards
Mark

I doubt you'll manage it. One of the common leak points is between the plastic frame and the metal of the roof, which NEEDS headlining out and sunroof out to fix it.

It will take an afternoon and a little patience - got to be worth doing it properly, surely?

I am just trying to seal mine now, first I gaffa taped up the glass to frame joint.
still leaked so I gaffa taped the frame to roof joint (from the outside)
no leaks!!
next I will remove the glass to frame seal and see what happens.
If its just the frame to roof joint thats leaking I will sikaflex it, if its both I will sikkaflex it all

if I could I would weld a steel plate over them!!!!!

we tape all our sunroofs up with gorrila tape...very long lasting and durable as you state its the plastic to roof joint that leaks
shutting the doors fast tends to inflate the cab / flex the roof at that point so all tape will give out in the long run my pal says welding on a plate is not a big job but you will of course lose the extra light in the cab on gloomy winter days

Could be leaking from roof bar front fixing. Try some sealant around this.