I am starting by stripping out the trim in the back as the leak I THINK is at the back. I will be doing both sun roofs and the roof bars, but will be doing it over a few days, today is strip down what I can.
Good luck mate....job worth doing. When my back sunroof was leaking, i only resealed the back one after stripping out the headliner. Now, a couple of years later, the front is leaking. Kicking myself for not doing both when i had the chance.
I spent a week stripping out the complete interior and water testing every area of the car and fixing each and every one of the leaks one by one
most are just bad design floors
But it was well worth doing I must of had the driest disco around
take your time and your only need to do it the once
If u are lazy or don't have the time.
We found on my mates disco that a thin carefully laid bead around 5mm of black sealer around the external plastic frame works and is hardly noticeable.
If water is passing the glass seal then that seal may just need removing, cleaning and refitting, the worse case will be replacing the seal.
Don't worry to much about drains (is not difficult to see them above the headlining) their only there to take any runoff of water if the glass is tilted, so don't do that, that's why they are at the front only.
If you have good air-con as i do then a easy fix is just to seal both roofs up from the outside with a tube of Sikaflex sealant, takes an hour or two and job done!
Good weekend, got back from running about mid afternoon, stippid it down, repaired front sun roof, refitted JUST the roofs before dark, refitted all the wiring and the head lining before dinnertime Sunday.
These sort of jobs seem a lot easier split like this