not sure if its exactly the same, but the symphony in an '04 A4 supports intelligent muting (pauses the cd, not just adjusts the volume) and yes plays the phone through the speakers.. I have the genuine kit for a Nokia6230, and it works well.
the only odd bit is that the syphony has fixed gain for the phone audio - so you adjust volume on the phone itself, not on the symphony volume control. You can get into the syphony setup and adjust the gain level.. but its v.loud on even the quietest. You can also choose whether the symphony routes the phone to left spkr, right spkr, or both. My perception is that is works best routed to left + right together.
hope this helps..
Ben
