Also, I was considering getting a touchscreen, or kit, but this limits my options even more. I was thinking of just going and getting a Sony or Clarion in-dash video receiver, that way I wouldn't have to run any radio or cd-audio through the computer or anything. For those of you with touchscreens, how useful do you find it?
I agree that with a touchscreen, everything is much easier and at the touch of the screen. This would lead to less distraction but a touchscreen kit isn't all that cheap to purchase or easy to install.
My cheaper alternative would be a Griffin Powermate and/or a Keyspan Digital Media Remote. I would be customizing my own interface and both of these can be programmed to mimic any keystroke. I figured with the Powermate, I'd be able to quickly and easily scroll through songs or playlists, and I wouldn't be limited to only being able to control what I see. For example, if I wanted to change songs or pause a song (via winamp hotkeys for example) while looking up directions on gps or something like that. Bear in mind that these aren't specific things I want to do, but simply examples to show pros/cons.
And NO, I'm not considering getting both.