I've also had problems with windscreen creaks and rattles. They seemed to be worse in cold weather and at one stage even sounded like the screen was going to fall out (bit of an exaggeration, but it really did sound bad).
Anyway, i've now done the fix that Munro suggested using the trim repair tape. The fix took about 1 hour. The only problem I had was that the centre part of the cowl seemed to be stuck to the windscreen, therefore making it difficult to raise the plastic enought to fit the tape in. I'd suggest two pairs of hands, one to raise the plastic and another to apply the tape.
Looking good so far; the fix appears to have worked as i've now gone a full week without a single noise from the windscreen.
Happy driving again!!
Thanks Munro!