Welcome to the forum!
That's another thought I had, instead of going through OBDII (which in my car, is quite slow, about 8 PIDs per second), interpret the factory gauge signals. That would provide live data feed instead of pulsed through OBDII. The thing is, that's way out of my league of knowledge. I'm a software developer, not a hardware guru. If I find anything, I'll let you know.
Check out http://www.dakotadigital.com they have sort of what I'm looking to do, but I want actual LCD screens instead of those LCD boards they use.