Dachtrager/dachzelt frage, Congo Cage & Cross bar?

[szenawissel]

Hallo,
 
First of all, I am sorry for my English, I promise to learn Deutsch as soon as possible, since I live in Germany now.
 
So, my question is to those who use Maggiolina roof top tent on their Congo Cage roof rack (I have seen great pictures of this combination from forum members especially from Herr cherokee
http://www.jeepforum.de/topic/84219-zeigt-her-euren-wrangler-mit-dachzelt/
 
How did you attach the tent to the Congo rack?  Is it a must to have the Congo Cage utility crossbars, or is there another way to fix it?
 
I have Maggiolina Adventure (the old type) and going to put it on roof of 2012 unlimited crd mountain.
 
Danke sehr in advance