OK, its not a CB radio per-se; I have an Alinco DX-70 amatuer radio that I have modified to broadcast on 11 meters (CB freqs). The main radio is mounted under the drivers seat and the remote head is mounted below the dome lights:
On models with EVICs this might be a problem, since I mounted it where the display would be. If nescessary I could relocate it to the dash or lower console. I also have a VHF/UHF radio installed on the side of the console:
It has done just fine there, but I have seen some people putting a piece of sheet metal behind the console to help with mounting (it is just plastic).