I've done interesting things like make the driver sit at 0/-100/0, essentially making the vehicle look empty if there were no other passengers.
One of the most fun things I have done is this:
I took the KettenKrad, and placed a regular wooden box over it, making it so that it was the only thing that could be seen. When you drive you sit on top of the box, which makes you an easy target. If you switch to position 2 however, you get placed at 0/-10/0, under the ground. Do this in Berlin with tons of wooden crates scattered around already, and you have a perfect method of hiding yourself.
The camera for all of the positions stay the same, unless you change their location, so I made the 2nd position have a top-down view of a lare area, to scope out an attack. It's awesome in a 2v2 or 3v3 game.