What did you think of the Neo people? My experience with them has been great so far. Great and friendly service and very informative!
That $20 cable is the Y-Harness that toyota makes. (Part #08695-00370) I still don't know what the hell it does, but hey, if it makes my ipod play in my car, then bring it on! It looks like it plugs into your CD changer port, and one side plugs into the Neo iON box and the last side just stays open. But the open side looks very identical to the CD changer port on your headunit, so maybe you can plug in an additional CD changer or PAC? I'm guessing that maybe this part is optional, but then again, i know nothing about this stuff.
I'm still experiementing with my iON, but this is what it seems like its doing. When I plug the iPod in, it automatically start charging. When I turn the car on and turn the radio on (FM mode) it just continues to charge. Once i press CD (or Mode on my steering wheel) it turns the iPod on, but it does not start playing. I usually have my iPod on shuffle mode, so if i press the next disc button, it starts playing the next song. After that I can either go up or down my playlist using track up or down (steering wheel OR HU). If i switch to FM or turn the radio off, it'll turn off the iPod. If you turn off the car without turning off the radio or switching it off CD mode, it'll continue to play. I found this out because the next morning, it was on song 179. I can't imagine if that drains your car battery or not. That kinda sucks. I havent gone through all the scenarios yet, but all i can tell you that this is a great product. the sound quality is great!
dan