You could use a small LCD display and feed it with a small ITX motherboard. You could integrate GPS and other things in it too. Whip up a desktop background that looks digital dash-like and with an instrumentation card like is used for industrial applications you are in business. A light Linux distro can be the OS.
The question is it worth it? I would do it just to say I did it, for the fun of it, but would live with standard analogue gages.