I think a bit of rubbing where the rear screen meets the deck is to be expected, especially going over rough road surfaces. I find it varies depending on temperature, humidity and when the top was last folded. I applied some Gummi Pflege:
http://lmgtfy.com/?q=Gummi+Pflege
to all the seals recently, and it certainly has helped.
I also wondered whether any other noises could be coming from the boot tray, which seems to be quite flexible...
I recalibrated my tyre pressures at the weekend. The backs were about 2 psi too low and the fronts were 2 psi too high! The car certainly feels a lot different now.
