As an example…
Take the BvhTriangleMeshCarTest and remove the back two wheels.
https://raw.github.com/away3d/awayphysics-examples-fp11/master/src/BvhTriangleMeshCarTest.as
eg
comment out
176 -177
265-268
and change camera so you can see
274
_view.camera.position = car.getRigidBody().position.add(new Vector3D(500, 120, 100));
The wheels constantly rotate even though the car is static.