Thanks for the insight Claude, I was referring to street use and not track use, but no mention was made of which gauges are "necessary". Lol, I have neither a 9 second car nor XFI.
If you have a scanmaster you could get away with leaving out the Coolant temp and Volts. I have Fuelpressure and boost on an A pillar pod to track fuel press VS boost at a glance. I have oil press, volts, coolant temp and fuel level in my GNX style dash. I'm switching from VDO cockpit to Vision over the winter and will ditch the Volts and coolant temp. I might move the Wide band to my A pillar and put the boost and either EGT or Oil temp in their places.