What I did was to use the aux input on the iPod adaptor to connect an external CD changer. I have a SONY FM modulated CD changer. Instead of connecting the output to the FM modulator I run the RCA cables directly to the iPod adaptor. The FM modulator part is just used as the screen/buttons for the CD changer.

I sold my in-dash cd changer for $150 on E-Bay too.

-Tad