Some hints about custom car with vehicle physics demo?

I need some hints how to move the car,
I added box and followed the vehicle graphics and physics entities
but instead of compound shapes I added one box
https://playcanvas.com/editor/scene/1045896

found sth like this:
https://playcanvas.com/editor/scene/971080

but why this car audi from demo above drives?
because there are separate wheels or suspension set correctly or what else?