This car model has been rigged for terrain and tire movement.
To control the movement, click on the green box underneath the vehicle and drag on your terrain.
Currently, the dummy has been fixed to a spline on the terrain. To move the car freely, disable the 'enable path' option under the dummy rollout by clicking on the green box.It can be found underneath the car on the back end.
Remember, to move the vehicle, use the green box underneath the car.You can create your own custom paths using splines to create your own movement.
Contact me if you have any questions.