I'm adding two 12v accessory power outlets (cigarette lighters) to the glare shield rather than in the front panel. Photos show the hole and the outlet on the right side. There is one on the left side, too.
The outlet is a marine-grade outlet so it has waterproof covers to keep crap from falling inside when not in use.
The outlet sits almos flush on the glare shield. Photo 2 shows it extended abobe just because I was too lazy to back off the nut to drop if flush.
I started the hole with a large drill bit then finished with the unibit.
If you do something like this, FIRST make sure you will not interfere with the behind-panel clearances required of your future instruments.