Kingpin
A car like that you want to show off to people and unfortunately the Department have taken issue with that, as rediculous as it may be.
This definitely can't be legal. They're threating to fire him for his hobbies, or what he does in his spare time. I think his superior has let the control go over his head, thinking he can do that. Don't get me wrong, he CAN do it, but the problem is he's not suppose to be doing that. (*egon)
They don't seem to respect the personal privacy of their workers. There is nothing illegal about building an Ecto-1 replica. Ok, so it may have something to do with the caution stickers or ambulance lights, that is understandable as it can cause confusion in the streets.
But forcing him to completely stop or be fired from his job? That doesn't make any sense because they have no right to be judging his personal hobbies. Again though, unless he files a complaint, nothing much we can do.