RNS Multi media interface problem...

Hello everyone! I am wilson from Hong Kong
I have a question on my own Audi's Navi system I hope you can take a
few mins to help me thanks!

I have a Navi-Plus before and I order a Multi media interface for my
unit! and now I change to a RNS-E unit and I did order a port and change
those RGB wire to the new port but it is not working in the RNS-E! after
I found a new Multi media interface unit from ebay and the
photos I see a CANBUS box together with the Multi media interface unit!

My questions is:-
1) Do I realy need to buy a new Multi media interface?
2) What is the CAN BUS box there for? (Since I have a CANBUS converter
already, is that any CAN BUS signals to tell the RNS-E wake up for TV or Video input? Because the old Navi-Plus are using the +12V to start the screen.....) :?
http://www.navplus.us/forum/album_pic.php?pic_id=281


Thanks
wilson
(From Hong Kong)