Nope, you're not the only one. I wanted to monitor various temps and pressures so added gauges for these functions.
My strategy was to capture the data using an Arduino microprocessor and transmit the data to a tablet across bluetooth. The current iteration has the tablet mounted in the steering wheel. I monitor oil, intake, transmission and engine bay temps as well as turbine inlet temp (EGT) and boost and vacuum pressure. I have a library of six different screens to present the data.
Since I'm using a tablet for display, I can also use it for navigation using stand-alone Android GPS apps.