I have a couple of CB's ( UHF & AM ) and unless you have a bullbar that have the bars level with the top of the bonnet, it can be hard to find a place if you don't want to drill a hole in the middle of the roof which is the best for reception. I had it mounted to the front of the bumper but it was hard to hear anyone behind you as you must have nothing in front of even the base. I finally decided that a gutter mount was the best and bought a nice cast alloy one with stainless fittings from GME model MB03 which is shown at www.gme.net.au
The next thing was to get wiring into the car without drilling a hole through the metal work so I placed the mount so that the wire ended up between both doors without touching it when they were closed and then fed the wire through a hole ( No.1 ) that was in the rubber seal. I just pushed it all the way down inside the rubber until it got to the join in the plastic under the dash ( No.2 ) as shown above. Then a hole was made by pushing a hole punch into the side of the rubber and pulling the wire out and then soldering the plug on and plugging it in. Very neat I think.
You can see here how and where I have mounted everything starting from the left it is: UHF unit with speaker, Inside - Outside temperature gauge, UHF remote head unit, Trip Computer, AM CB, Brake Controller, Subwoofer Amplifier.