For a sound system for everyone around us: The CB in our truck has not only the built-in speaker (near the ceiling in the rear seat of the cab, but a hard-wired speaker, on a magnet mount, in the rear of the bed. There's a speaker-selection switch on the dashboard near the driver. That switch allows choosing between the various loudspeakers. When we're in staging, for instance, I use the magnet one in the back and attach it to the outside of the body, and turn up the volume so those around us can hear the CB if they want to do so. Sharing the CB like this is pretty common in the moving lines - and you'll often see folks gathering around the speaker during runs.
It's not practical to have enough stationary-mounted radios to give audio coverage all along the lines, and that's why I came up with the present system.
Let's see -- it's ten years this year for us and I'm getting things more and more "just right" for our racing adventures. I wonder if I'll ever get EVERYTHING set up perfect?