I went through the same uncertainty before I bought mine, this is what I know.
You wont see the Connect Nav+ listed as supported by Dension because officially it isnt. It will only work if you flash unsupported beta firmware onto it.
eg on this link
http://www.ipodcarkitdirect.co.uk/iP.../Compatibility
it says
Please note: This adapter is not compatible with the Alfa Romeo Navigation manufactured by Magneti/Marelli.
I bought a Blaupunkt one used off ebay and flashed it. Works a treat.
As I understand it the one for Alfa, Fiat or Blaupunkt is the same. If you search the web on the Dension part number ILBP0834 you will find lots of places selling the unit as Alfa / Fiat / Blaupunkt.
I just found a link with all the part numbers, you can see they are the same.
http://www.speed-detectors.co.uk/cat...lus-p-152.html
Hope this helps.