Porsche style fan shroud
 

The company that creates my rear window spoilers (link), also produces a Porsche style fan shroud for the type 1 and one for type 4 engine. Both are for the 260 mm Porsche fan.

I want to see if people are interested in this fan shroud. The price is 90 euros.

http://www.gerrelt.nl/roofspoiler/koelkap/koelkap1.jpg

http://www.gerrelt.nl/roofspoiler/koelkap/koelkap2.jpg

They are made out of fiberglass. Maybe a carbon fiber one is possible too, I'll have to ask.