There are several threads about installing the boost gauge but they all have one thing in common and that is the location requires the driver to take their eyes off the road or it has clearance problems or disables an AC event etc.
Here is one that requires no drilling inside the cockpit ( sorry I am a pilot) is very visible and leaves the AC vent.
The only difference between this post and the darkmini how-to is the location.

Take a look at the pics, it might work for some.

 

Nice! What all did you have to remove to route the wires/ plumbing?

 

That is the nice part...nothing!!!!
The pressure tube and wiring go straight out to the base of the windshield into a groove there, then left around the end of the dash and through the left end inspection panel. This install requires NO drilled holes anywhere and the few inches of exposed stuff can be easily hidden. The mounting screw is just a longer version of the factory installed screw.
If you look at the middle pic you can see the wire/tube. I colored the white tubing with a magic marker.