Hi folks, just catching up here on this. Thanks again for all the help and feedback, really apprecaite it.
Anyway, as it was easier than taking the trims out I just basically went round taping up all the body/window/door joins until the leak stopped which thankfully I think it now has. And.... it looks like it is the windscreen and maybe the rear screen as well although that is more difficult to be sure of - just masses of condensation on the rear screen. So first job is the get the windscreen seal fixed - incidentally whilst doing some work on it, I noticed marks of the glass lifting suckers they use so perhaps it has had a screen changed and not sealed very well.
Sense of relief here. I was on the road yesterday and it was driving and riding so well I couldn't accept a water leak ruining it and every time I think about changing the car, it is the usual unanswerable question, just what do you replace it with? So let's fix the windscreen and see if that is really it.
Thanks again all 🙂