Just found this US company that sells sliding sunroof kits for Bugs, Buses and Ghias

http://www.streetbeatcustoms.com/slidragvolwa.html 

They look pretty good at $470 U.S plus shipping

Does anyone know of any being fitted over here?

do some research on them on shoptalkforums or samba. i remember i did not so long ago and got very mixed oppinions of them. if you are interested in getting one for a late beetle i know StenGuns has a complete britax kit which i believe were available for 68+. not sure if it was a factory thing or not but i think he was selling it considerably less than 470us.

nick