Deckster

Hey everyone! I have a question about my current head unit, and converting to a aftermarket head unit. First thing first, I have a 2006 Audi A4. I have a Bose sound system in my care with the symphony 1. The car also has built in XM since it was a part of the package that the previous owner purchased. But here is the kicker, do you know of any double din radios that would support the XM that is already built in so I wouldn't have to purchase an extra antenna or anything like that for these aftermarket head units. Or maybe I wouldn't need to purchase an extra dongle just maybe a converter? I have no idea, so this is why I am asking everyone here. Please give your input on whats the best way to go! Thanks a bunch!

Dex