Ok, I now understand the requirements for a small database

Userland tag browsing sounds like a fine compromise - especially if I can redefine the Knob-press to call it up.

And I know that allmusic.com's reviews are hit and miss - but being able to call up a detailed review adds to the Wow factor for unsuspecting passengers, and I think that the best in-car MP3 player in existence should strive to Wow the masses in as many ways as possible....Next thing I'll be suggesting is coverart, added as a custom ID3 tag that can be viewed with an image-panner app!