You could set up one using the kenwood FM modulator since it comes with a display and controls to hook up.. then use that aux setup to connect the CD changer audio to the keg / phatbox's RCA outs.
So far that is the plan, This should get me past the dreaded fequency loss of an FM modulator.
I have requested a wireing diagram from the12volt.com for this car. If I can figure out the way the factory changer is controlled, maybe an interface can be created. I know many people that would be intrested.