I have recently fitted an I-wire cable to my CR-22. I ordered it from a chap in America. It cost $49 and I was stiffed £20 import duty. It attaches to the autochanger out on the back of the radio and then pops out in the left foot well. It came with really good instructions and the radio removal keys. It took about 30 min to fit. I added a Brodit angled mount and adjustable Ipod bracket (about £30 for both). It works well as long as you turn the backlight on the ipod off (otherwise there is a bit of a whine through the speakers). It charges the ipod but you still need to operate the ipod unit to change tracks.
http://www.iwirep.com/products/iwirep-220-ipod
http://www.amazon.co.uk/DSL-Brodit-Porsche-Brodit-...
http://www.amazon.co.uk/Puregadgets-Brodit-Passive...
All the best.
http://www.iwirep.com/products/iwirep-220-ipod
http://www.amazon.co.uk/DSL-Brodit-Porsche-Brodit-...
http://www.amazon.co.uk/Puregadgets-Brodit-Passive...
All the best.