Re: Non ipod user
I was struggling with this problem a few years ago, not sure if any new products are available these days but here is what I learned: Ipod vehicle integration into aftermarket units took forever, and microsoft being less popular is taking even longer. Most USB compatible head units do not support zune, I've heard of certain units that will but it's hit or miss, I'll look around. An AUX input is your best bet. Get a good AUX cable and sound quality will be almost identical to USB through average systems. But unlike USB controls, you will have to control music through your player, not your stereo. If you hate that idea, get a USB capable unit and load up a thumb drive with whatever you want, you will just have to organize the folders by artist or song or whatever but you will be able to navigate menu's through the deck at least.
I guess what I'm saying is, you should find a cheap used ipod because unfortunately that is the best option with aftermarket decks.