I am also a ham, I think that getting a wire for antenna out to the bed from the cab should be pretty easy, there is surely a grommet somewhere for brake light and trailer wiring, once you get into the sails finding a good place to come through shouldn't be too much of a challenge. Drilling might pose a bit of an extra challenge but I have every bit of faith that I will find a way to get it done. If Tesla expects to sell them as work trucks they probably have already thought about it and started the standard documentation that roads crews, police, construction crews, park rangers, etc will need to give their radio outfitters for the UHF radios they use.