Thanks everyone

I'm still working on a few little irritations here and there but so far I think it is easier to use than the stock radio! Seriously. Having the huge front row display makes it really easy to scroll through a ton of artists/albums/songs/playlists.
Plus being able to choose from any of my digital collection at any time - priceless.
And the carnetix psu puts the mini to sleep when the ignition is turned off. So when I start the car, the mini just wakes from sleep (read: no waiting for booting). Very pleased so far.
As far as updating is concerned, I've been lazy and just set up VNC for now. Eventually I'll tunnel it through ssh, set up a cron job to update my library and grab the latest podcasts at night (via 802.11). I still am looking for a good
small bluetooth keyboard that I could possibly store in the glovebox... not having too much luck yet

Can anyone recommend one?