Why not install a touchscreen 7" monitor in your dash, and have a carputer? Mount the reasonably powerful laptop w/broken screen in the trunk, wire it in to a power supply, attach a USB GPS antenna, and go from the audio out to the amp / speakers?
All the MP3s you can store, instant access to the OBD-II information, "free" GPS, and (with Backtrack III or the like), war-driving capability. Have it get email from your wireless access point and read it to you on the way to work. Keep a copy of the local yellow pages on the drive, and look up the nearest Cuban restaurant.
There are a lot of great "front ends" out there, and most all of them are skinnable to your heart's content.
Hope that this helps / is something in which you might have interest.
http://www.mp3car.com/