I remember I used to go to a lot of car shows and saw the silliest gauge mounts possible. My favorite was either the cupholder with the gauge facing straight up, or the glovebox. A lot of the glovebox gauges weren't even angled toward the driver, I never understood how that would be usable. Obviously all that was for show, but some of these cars had turbo setups and the boost gauge would be mounted in the glovebox...
On my old car, I had a custom 4 gauge A-pillar pod w/ boost, oil pressure, A/F, and fuel pressure. On my wife's old car, 2 were mounted on the pillar and 2 were mounted right behind the steering wheel. Things can go wrong in a second and if the gauges aren't visible without turning your head, they won't help. I remember several times my car boost spiked and if I hadn't backed off right when I saw it, things could have gotten ugly. Or when my oil pressure dropped to zero all of a sudden - turns out the sender just failed, but that was a scary couple of minutes diagnosing it on the side of the road.