Maybe you've already checked this, but are you sure the ID3 information in each mp3 is correct in your iTunes software? Garbage in - garbage out, you know. If you're using mp3s with poorly formed tags, the car will simply read the info it's given.
I have a huge library of mp3s (maybe 40,000 tracks) and many of the tags were crap. I found this software called TuneUp (
http://www.tuneupmedia.com/ ) and was astonished at the results. With a little time and patients, I cleaned up almost all my tags. I could accomplish in minutes with this software what would've taken me days or weeks to do by hand.