Have not seen a post related to this problem-maybe I did not search enough. Here's the problem. I have been experiencing a leak on the left front corner of the sun roof. It is a steady drip when it rains hard. Tonight I took a coated piece of wire and pushed it down both drain holes...seemed like it was about 3 feet or close to it and could not go further. I then took some vaseline and lightly coated the rubber seal...it was not dry by the way. No where else leaks. We'll see what Monday (Oct 25th) brings....suppose to rain then also. Appreciate any comments you may have.
Thank you,
Bill
'02 Jag VDP

 

I think you are doing the right thing. The drain tubes are the key to the sunroof not leaking. The seal is not a water tight seal, it is more for noise and dust.

Check out this post there is an interesting idea for clearing the tubes with a can of compressed air commonly used by computer technicians.

 

Is your rear 1/4 sunroof headliner panel properly in place? It is what channels water (as there always is some that gets past sunroof) to the drains.

Otherwise, you are probably correct that the drain tube is plugged.