Multiplayer users should be able to join as a passenger on a drivers car. They would be able to look around. This would be amazing for VR.

It is, yes

All I do is place the movable camera (I think it's the 3rd view, between driver view and heli-chase cam) in the approximate position of the passenger's head - et voilà! Spectating from the passenger's seat!

@TechEdison: Here you go