I went a slightly different route. As I'm a technophobe, I own no iPod, so had no need for MP3 jack. I sent the existing AM/FM factory radio to Gary Tayman at www.taymanelectrical.com to replace the existing guts with electronic guts and a new harness. Went with dual cone 4X10 for the front and new 6x9s in the back with new wires. The rear has a 6-disc changer compatible with the new radio.
Control of the changer is effected by a separate control panel which I placed on a bracket I fabbed that swings out of view when not in use. When swing up, it stays up by velcro that is stuck to the back of the bracket. That strip adheres to the other half which is stuck to the bottom of the radio.

The control panel also has a separate remote which I can keep under the seat, in the ashtray, or on top of the visor.

When the CD is turned on, it automatically cuts out the radio, and control of the tunes is by the separate control panel. When the CD is off, control of the radio is by the radio panel itself, of course. The rheostats controlled by the knobs have been modified so that they control not only volume, but also balance, fade, and tuning. The tuning knob is actually mostly unchanged, but the tone control of the volume knob is multi-function: When the tuning is brought to full scale on one side, the tone control is a balance control. When the tuning control is brought to full scale on the other side, the tone control is a fade control. Once balance and fade are set, you don't have to mess with them much, so it's pretty easy to work.

This setup did require slightly modifying my existing harness to wire in the new 12-pin plug.
If I had to do it over, I would have sent Gary a different plug to use. EBay sellers have some Acura/Honda stereo harness plugs - male and matching female - that are way more robust. The plug in this setup boogered up a few pins after the second test fit.