Hoping somebody could help me......

I want to somehow incorporate the factory installed 6 cd changer to be able to play MP3's. I am trying to avoid buying a whole new system as this would defeat the purpose. My other thought was to buy an IPod (which I have been wanting to get for quite some time) and possibly use some sort of adapter to hook the IPod to the radio so I can listen to MP3s that way? If I go with this would it then delete the use of the steering wheel radio/cd controls? Any help would be grateful