help change my script to work with rigidbody

hey my current movement script is made to work with char controller, but the car cant rollover or anything, could someone please help me change it to work with rigid body

Code (csharp):

1. //moving around
2. var speed = 3.0;
3. var rotateSpeed = 3.0;
4. //shooting
5. var bulletPrefab:Transform;
6.  
7. function Update ()
8.         {
9.             var controller : CharacterController = GetComponent(CharacterController);
10.             transform.Rotate(0, Input.GetAxis ("Horizontal") * rotateSpeed, 0);
11.             var forward = transform.TransformDirection(Vector3.forward);
12.             var curSpeed = speed * Input.GetAxis ("Vertical");
13.             controller.SimpleMove(forward * curSpeed);
14.    
15.      if(Input.GetButtonDown("Jump"))
16.      {
17.           var bullit = Instantiate(bulletPrefab, transform.Find("shootPoint").transform.position, Quaternion.identity);
18.           bullit.tag = "Progectile";
19.           bullit.rigidbody.AddForce(transform.forward * 3000);
20.      }
21.      
22.  }
23.  

 

Rigidbodies and CharacterControllers generally don't play very well with each other so you should choose one approach or the other. If you want rigidbody physics, you will probably want to look at using wheel colliders. You might find the JCar script from the Unify wiki a good starting point and there is also a car tutorial available from the Unity website.