roight!
The problem has finally been sussed..
going through the common problems
The windscreen seal is good, I had no reason to believe there was anything wrong with it..
Sunroof drains are clear
The seam sealant on the roof was all intact
So it left my old friend the sunroof frame/glass itself..
The sunroof seal itself is wrapped around the glass frame which in turn is sealed to the glass with a mastic, the steel that makes up the frame is very poorly protected and by design water will find its way under the seal and just sit on the frame between the glass and after years of moisture the frame rusts and swells which breaks the seal between the frame and the glass, the subsequent issue is water finding its way under the seal and on to the inside of the glass/frame which in turn will wick down the glass and on to the headliner..
The prime suspect!
Pictures!
The frame around the rear of the glass wasn't remotely attached to the glass and even with light pressure from my wire brush it was flexing and bending, if I put my torch on the inside and the beam of light could be seen escaping through the break
You can see the seal design "just" and how water finds its way under.
All I had available was white silicone which isn't ideal however it'll work, the way to do it is to apply a thin but continuous bead around the frame making sure it makes its way under the glass slightly..
A small caveat is you must make sure the bead is thin, otherwise the seal will sit proud and the roof won't close!!
And done!
Apologies for the long post, but nothing annoys me more than a thread that ends without a solution!
Symptoms were "to compare"
1) Condensation on the inside of the sunroof glass that would sometimes drip on to the centre console,
2) Both front corners of the headliner wet.
3)
The sunroof seal itself isn't really a seal, its main job is to slow down the water to allow the drains to carry it away without being overwhelmed, its also a draft/wind noise reducer..
H