I have the factory E46 "business" cd player (AM-FM-CD), and I was going to add a XM. I need to know if there is an "AUX" port in the back, for the use of a factory CD changer if anyone has verified this, I'd like to know, or even better if someone has installed a Delphi in thier car using the "business" stereo, how exactly was it hooked up? I see there are lots of PIE or Blitzsafe options, but I really dont know if they will work on my stereo or not without actually pulling the radio out. any ideas?