Wolf, stop by the camping section, lots of roof top tent banter in there.
http://www.expeditionportal.com/forum/forumdisplay.php?f=30
I have the Maggiolina AirLand model.
Mike S. on the forum
in this thread runs the USA site of Autohome.
www.autohomeus.com
The Italian site where they are made is
www.autohome.it
You do lose pretty much all of your roof rack with the Maggiolina models and the Columbus models by Autohome, but they are really great tents and can be left on all year.
Mine has been on my roof since March of 2008 and looks brand new still, even after being exposed to the elements and UV light from the sun.
I keep Marine wax with UV inhibitors in it, and it keeps it in great shape.
Here are a few of my favorite pics of mine.
Yes, I am a picture whore :sombrero:
There are many different roof top tents though discussed in the camping section.
And this video here from the Autohomes US site always gets me in the camping mood.
http://autohomeus.com/video/video2.swf