I don't see why the expensive one pioneer makes ( the CDIB something I forgot the numbers) wouldn't let you use your HU to control the I-pod. I had the expensive one and it wasn't that great, i recommend buying the 30 dollar one from best buy.

The expensive one would only let you control the I-pod from the head unit, and it sucked because you had to scroll through every artist individually, one by one.

Buy the monster cable that has a few connection on it. It has i-pod connector, a headphone connector and a y-cable connector. I have that one now and it lets you use the I-pod to control what plays.

They are sometimes a bee-otch to put in but if ya need help with it just pm me.