So I slogged through the Dension web site. According to their list of Audi configurations, it seems there's some ambiguity. Do I have a Symphony II stereo or a "Symphony GEN II+"? Probably for former, but it's hard to tell. That gives me five different Dension products to choose from. Ideally, I'd like Bluetooth A2DP, but my car already has Bluetooth for making calls. Do these play nicely together? I have no idea and haven't been able to find anybody posting anything useful on any forums. See, for example this post, where the last entry (from 2010) ambiguously says "Yeah this thing works perfect for A2DP. We are still testing the bluetooth functions because they are very unstable. Contact us if you are interested."

If I'm going to tear apart my dashboard, I really want to do it only once.

EDIT: For the record, the face of the stereo says "Audi Symphony", making it further ambiguous whether I have a Symphony II or Symphony II+.