The Arduino platform lends itself nicely to working with all manner of sensors, interfaces and therefore measuring data types and signals with ease. And thus with some planning you can put all this to work, just as Instructables member TankMorph has done with his information centre for a 1990 US Ford Mustang.
The factory speedometer has been remove, and in its place an Arduino with a large character LCD, which is also connected to various sensors in and around the vehicle along with a GPS module. This allows for speed, temperature, engine temperature, trip meter, heading, real time and more to be displayed for the driver. It's a great way to modernise older cars or just add some "Knight Rider"-style pizazz for fun. Furthermore there's a lot of scope for logging vehicle paramters for later analysis.
In some jurisdictions there can be laws with relation to modifiying odometers, so check with your local agencies. However for more information and the Arduino sketch running the system - visit the project's Instructable page. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.