It would be useful if you could post a picture of the offending joint....

Early cars had a rather thinner rubber seal around the windscreen. On a car of nearly 6 years old the rubber will be less supple that is used to be and replacing this with a thicker MK2 type may well be the answer, it's a pretty straight forward DIY (ie don't pay a dealer to fit it). Window adjustment might cure the issue but with the older seal there is always a bit of luck involved.

When adjusting the window the glass should touch the underside of the rubber seal NOT the side of it as I have seen many times. If the glass if forced against the side of the of the roof rubber it strains the window lift mechanism and can cause problems in the future.

Tim

 

Greg, does the glass sit on the 'outside' of the seal, rather than in the centre were its supposed to be?
My old '97 F used to do this. I traced the problem to a broken window stop (early MGF's are renown for this).
As Tim says, changing the seals to the later type on a car of this age would not be a bad thing. (Appart from for your wallet that is )

 

I'm having the same problem with water leaking down the drivers window, the glass sits against the seal rather than going into it.

TimDVA, you say it is pretty straight forward to replace the seal with the thicker MK2 type? where could I purchase this and how straight forward is it? any instructions?
Any tips greatly received.....:s2h:

 

Greg, while it is obviously best to fix the leak, there is no need to get a wet bum.

The water leaks onto the corner of the seat and runs to the bit you st on so ...

Keep a small towel in the car (make 4 from a normal handtowel), fold it in 2 and drape over the front corner of the seat. The leak will drip onto the towel and stop it running along the seat onto the squab.