heres the oem crossfire radio manual for radio 6806, sec. 6 describes the phone function, I might have mis-read but I think you can get the phone to operate in stero mode.
I don't quite understand the LHD left hand drive or RHD right hand drive modes.
nevermind it won't upload, I can email it to you if you want
OK I found a link of the Becker pin outs over at this crazy guys website, check out how much crap he's got in his crossfire, its color coded too.
http://4x4icon.com/crossfire/pioneer_tuner/index.htm