Multicrew Management?

[LQuinze]

With Tank Crew incoming and the possibility of a greater emphasis on multi-crewed vehicles, I'd like to see the possibility of giving more granular control over crew slots in multiplayer, especially if you wanted to only allow certain people to crew the vehicle with you. As far as I'm aware this is mostly an on/off feature at the moment - either the server allows multicrew or it does not. The simplest idea in my mind would be allowing passwords to be set on crew slots, so that only certain people could take the seat.