Oh my goodness I like how small that is! Im looking at an all-in-one mic and it comes with a small box like yours. I did read someone had one and mounted it underneath the glovebox, so it is completely hidden..... and then I was thinking a magna-mount- since SHE is my daily driver....I hate clutter too....
What is the box under the seat with all the red cables? Is that where the antenaae and cb get 'grounded'? I like how the other box fits so compactly under the dash.
That box under the seat is the new fuse box I installed to handle the power for the CB and additional USB power outlets I added inside the car (for charging phones, pads and cameras).
The larger wire from the fuse box goes directly to the battery so I am not attaching to any existing power lines or fuse boxes. Smaller wires are the hot wires that go to the CB and power outlets. This was suggested to me so I don't accidentally screw up the computer system and turn my car into a giant paperweight.
Grounding for all is with separate wiring inside hooked to the car frame. Antenna is grounded through the mount on the hood. If you want to see any additional photos let me know what you want to see and I'll post them for you. Even though I have a Subaru wiring like this will work on different cars.
My CB is completely hidden under the dash and the mic can be easily disconnected and put away also. Even though the CB comes with an in-wire fuse I still put the hot wire though a fused outlet on the fuse box, not needed but thats ok for me.