One of my favorite bits of the GT-R, the R34 specifically, is the incar lcd that shows various status displays. Has anyone tried to build something like this? The lcd part would be easy, but has anyone tried to tap into the onboard sensors for engine information?

 

You can already do with with some of the various higher end OBDII scanners. I think there's even an aftermarket company that makes an aftermarket guage cluster that retrieves info from the OBDII port.

 

Look at the Pioneer VDP-1 unit it shows quite a bit of info by using gps and an accellerometer.