I like this idea, not so sure about the use of an expensive arduino thought. I like the one comment where the gent suggests just using an old android phone and a bluetooth OBD2 scan tool. (quot below)
Or you could pick up an old Android phone and run the Torque app with a $10 Bluetooth OBD2 scan tool and window mount. Cheaper, FAR more attractive, and far more information available to display <Qout
Either way, the rest of the materials would be worth noting (
- Large Fresnel Lens: $1.80 (It really doesn’t matter which one you buy as long as its at least ~220mm long.)
- Teleprompter Glass: $15 (Get the 7″ by 4″ custom size.)
- 4 Suction Cups: $3/$1.50/pack of three (You can use any suction cups you want, just make sure they can hold the glass safely.)
http://lifehacker.com/how-to-build-a-heads-up-display-for-your-car-1129913775