Hi, I have recently fixed I think, (well it dont drip no more) My front sunroof on my TD5. The drains were blocked. The water was pouring inthrough the sunroof, down the winding handle, head lining over the wind screen and through the light.
The way to prove this is to open your sunroof and pour water into the left and right side of the sunroof tray, as much as possible without it dripping into the cab and watch for where it comes out. It should drip out at the back of the front mudflaps. IF it doesnt, your drains are blocked.
Now you aint gonna get at them from the sunroof, coz the sneaky buggers at landrover have put them right in the corners of the sunroof tray, so the head lining has to go.
I managed to do it by removing the sunvisor, overhead bins, and handle over the driver door. The lining can then be pulled down just far enough to see the hose, pull it off and blow it out. Re make the end off before you put it back though, as it if is a loose fit it will just leak again.
I also took the glass off the sunroof and removed the rubber seal, cleaned it and the tray where it sits, and glued it back with black silicone.
This has fixed this drastic leak. Check it out it may work for you.
Cheers
Colin