I made this last weekend , and have been checking it out all week.
The iPhone mates nicely into the A4's system
It will play the iPod audio as a well as the iRadio station through my cars audio system.
The phone will ring through the audio input also.
I modified a standard iPod base to include a cable for audio out and power in.
This cable then would get soldered to the connector here in the base.
Sorry, I don't have a pic of that.

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Other end of the cable goes to the audio-in of the adapter for the Audi Head Unit, and also to ignition-switched +12V.
The iPhone power connected at this point on the connector will take 8-30VDC.
Note the Head unit sez 'CD' when in fact, the adapter tricks the H/U into opening the audio-inputs.
Thats' how I get iPhone audio out and power in.
Yes, it charges the iPhone, and pauses the iPod stream when the ignition is turned off, restarts the iPod play when the ignition comes back on.
