There have been posts on this before in this forum but in short:
The Connects2 interface served me pretty well with the Symphony despite its limitations: The interface is supposed to map CD changer buttons to the first playlists on the iPod but that never worked. What did work very well was:
* Skipping tracks up/down using steering wheel controls or HU controls
* Playing/pausing on HU mode change or power on/off
I have one "top rated" playlist that I sometimes revert to but mainly I select music by browsing so I never missed the stuff that didn't work.
The Connects2 units seem to consist of two boxes: One that translates whatever language the car uses - in our case I-bus - to Sony(?) CD changer protocol and then another box that does Sony -> iPod.
I say Sony because they do a lot of Sony changer stuff, but it could also be AI-net (Alpine) because the cable between the boxes looks just like an AI-net cable.
Here's another picture of the Connects2 with the Symphony:
