Cannot make initial speed for the Player car using AIDriverToolkit

i make a car race using AIDriverToolkit plugin i need the car to walk automatically with initial speed not need to press up key to let the player just rotate . i try to do it by replace the behavior of Input.GetAxis("Vertical") to 1 and put it in Update method but it doesn't work. i try to change the dimension of it using

         this.transform.position = new Vector3(transform.position.x , transform.position.y , transform.position.z + .1f );
 

but i think it is not the best practice. thanks in advance for any solution.