I called my dealer and he put me onto someone who put me onto someone else who asked for the same details I'd already given in the email which I supplied again and still never heard back from them...
So I called the Factory Museum direct - see
http://www.porsche.com/usa/dialogue/contactandinformation/museum/The lovely Sigrid Mauz has booked us in for June 6th for the Zuffenhausen Factory Tour in English. And yes it's free, and no you don't have to wave a Porsche key ring at them.
Hope that helps others.
BTW When I read Wonderbar's post about seeing an aussie dealer at the factory delivery - I thought I had been didled by my dealer. So I called Melbourne and it turns out that for some strange red-tape reason to do with license plates Australian's can't get factory delivery.
This is a damn shame. I think I'll take out some angst on a hire car at Nurburgring.
;>