i know how to do this in cars and trucks that came standard with xm radio. did it on my buddy's saturn. i know a couple people on here with the lower tape deck have done some projects where they converted the tape deck into the input

 

Okay, I finished it. I gotta do a bike medic thing in the morning for a marathon, so don't expect pics until a few days from now. I tried hooking up the wires in the link, but found that the noise from the CD was stil loud enough to be heard with the iPod playing, so I cut out the CD input altogether and run just the iPod. I do need a CD for the radio to recognize the function, but otherwise I'm happy with it. The input is in the ashtray with an extension hooked to it, so when the ashtray door is up, you don't see anything.