This tickled me as a good idea. Unfortunately I don't think it would fit on a Fiat 500. : http://www.instructables.com/id/Roof-top-car-camper/
Brilliant idea. Loving the Scirocco. You can buy something more useable on eBay. I looked at roof tents when considering a tin top. They loom like safari tents. Brilliant idea.
Roof tents are the business. Were considering one for the back of our westy (accessible from the window in the roof when elevated) when the kids get too big for the cab hammock.
Ooh roof tent on the back of a westy! that sounds interesting which model have you been looking at? as we have two kid's and our youngest is just on the verge of of getting to big for the bunk. Chris