Just saw this article on Autoblog, looks mighty cool. Would be great if you could drop this where the Navi is instead of having a bunch of gauge pods for you FI guys. It's basically a linux based computer, but it can plug into your ODBII port and display any number of things, and it can also hook up to GPS or any number of sensors.
I don't really know too much about it, but it looks pretty cool. According to Autoblog the product is available now for like $695.