I’m a friend of optional stuff, since it serves all sides.
Couldn’t have said it better.
@imajor: I agree the depot doesn’t really andd anything to the game. Its nice and realistic but only used to buy and sell vehicles. No maintenance. In CiM 2 the depots are used to store vehicles and have vehicles as reserve in case the line needs more vehicles for a rush hour or a traffic jams. In TF depots are kind of useless.