CarScript

public var PlayerCar : Transform;
public var Grounded : boolean = false;
public var CarGravity : float = -20;
private var accel : Vector3;
public var throttle : float;
private var deadZone : float = .001;
private var myRight : Vector3;
private var velo : Vector3;
private var flatVelo : Vector3;
private var relativeVelocity : Vector3;
private var dir: Vector3;
private var flatDir : Vector3;
private var carUp : Vector3;
private var carTransform : Transform;
private var carRigidbody : Rigidbody;
private var engineForce : Vector3;

private var turnVec : Vector3;
private var imp : Vector3;
private var rev : float;
private var actualTurn : float;
private var carMass : float;
private var wheelTransform : Transform[] = new Transform[4];
public var actualGrip : float;
public var horizontal : float;
private var maxSpeedToTurn : float = .2;

public var frontLeftWheel : Transform;
public var frontRightWheel : Transform;
public var rearLeftWheel : Transform;
public var rearRightWheel : Transform;

public var LFWheelTransform : Transform;
public var RFWheelTransform : Transform;

public var power : float = 300;
public var maxSpeed : float = 50;
public var carGrip : float = 70;
public var turnSpeed : float = 3.0;

private var slideSpeed : float;
public var mySpeed : float;

private var carRight : Vector3;
private var carFwd : Vector3;
private var tempVEC : Vector3;

private var hit : RaycastHit;

function Start()
{
    Initialize();
    Physics.gravity.y = CarGravity;
}

function Initialize()
{
        carTransform = transform;
        carRigidbody = rigidbody;
        carUp = carTransform.up;
        carMass = rigidbody.mass;
        carFwd = Vector3.forward;
        carRight = Vector3.up;
        setUpWheels();
        carRigidbody.centerOfMass = Vector3(0,-0.7,.35);
}

function OnCollisionEnter(collision : Collision)
{
    if(collision.gameObject.tag == "Terrain")
    {
        Grounded = true;
    }
}

function OnCollisionExit(collision : Collision)
{
    if(collision.gameObject.tag == "Terrain")
    {
        Grounded = false;
        throttle = 0;
    }
}

function Update()
{
    carPhysicsUpdate();
    if (Grounded && ((PlayerCar.localEulerAngles.z >= 0 && PlayerCar.localEulerAngles.z <= 50) || (PlayerCar.localEulerAngles.z >= 310 && PlayerCar.localEulerAngles.z <= 360) || (PlayerCar.localEulerAngles.z <= 0)))
    {
        checkInput();
    }
    else
    {
        throttle = 0;
    }
    if (Input.GetKeyDown(KeyCode.Return))
    {
        if (Grounded)
        {
            PlayerCar.localEulerAngles = Vector3.zero;
        }
    }
}

function LateUpdate()
{
        rotateVisualWheels();
        engineSound();
}

function setUpWheels()
{
        if((null == frontLeftWheel || null == frontRightWheel || null == rearLeftWheel || null == rearRightWheel ))
        {
                Debug.LogError("One or more of the wheel transforms have not been plugged in on the car");
                Debug.Break();
        }
        else
        {
                wheelTransform[0] = frontLeftWheel;
                wheelTransform[1] = rearLeftWheel;
                wheelTransform[2] = frontRightWheel;
                wheelTransform[3] = rearRightWheel;
        }
}

private var rotationAmount : Vector3;

function rotateVisualWheels()
{
        LFWheelTransform.localEulerAngles.y = horizontal * 30;
        RFWheelTransform.localEulerAngles.y = horizontal * 30;

        rotationAmount = carRight * (relativeVelocity.z * 1.6 * Time.deltaTime * Mathf.Rad2Deg);

        wheelTransform[0].Rotate(rotationAmount);
        wheelTransform[1].Rotate(rotationAmount);
        wheelTransform[2].Rotate(rotationAmount);
        wheelTransform[3].Rotate(rotationAmount);
}

private var deviceAccelerometerSensitivity : float = 2;

function checkInput()
{
        if (Application.platform == RuntimePlatform.IPhonePlayer ||(Application.platform == RuntimePlatform.Android))
        {
                accel = Input.acceleration * deviceAccelerometerSensitivity;

                if(accel.x > deadZone || accel.x < -deadZone)
                {
                        horizontal = accel.x;
                }
                else
                {
                        horizontal = 0;
                }
                throttle = 0;

                for (var touch : Touch in Input.touches)
                {
                        if(touch.position.x > Screen.width -Screen.width/3 && touch.position.y < Screen.height/3)
                        {
                                throttle = 1;
                        }
                        else if(touch.position.x < Screen.width -Screen.width/3 && touch.position.y > Screen.height/3)
                        {
                                throttle= -1;
                        }
                }
        }
        else if (Application.platform == RuntimePlatform.WindowsEditor || RuntimePlatform.WindowsWebPlayer || RuntimePlatform.WindowsPlayer )
        {
                horizontal = Input.GetAxis("Horizontal");
                throttle = Input.GetAxis("Vertical");
        }
}

function carPhysicsUpdate()
{
        myRight = carTransform.right;
        velo = carRigidbody.velocity;
        tempVEC = Vector3(velo.x,0,velo.z);
        flatVelo = tempVEC;
        dir = transform.TransformDirection(carFwd);
        tempVEC = Vector3(dir.x,0,dir.z);
        flatDir = Vector3.Normalize(tempVEC);
        relativeVelocity = carTransform.InverseTransformDirection(flatVelo);
        slideSpeed = Vector3.Dot(myRight,flatVelo);
        mySpeed = flatVelo.magnitude;
        rev = Mathf.Sign(Vector3.Dot(flatVelo,flatDir));
        engineForce = ( flatDir * ( power * throttle ) * carMass);
        actualTurn = horizontal;
        if(rev < 0.1f)
        {
                actualTurn =- actualTurn;
        }
        turnVec =((( carUp * turnSpeed ) * actualTurn ) * carMass )* 800;
        actualGrip = Mathf.Lerp(100, carGrip, mySpeed * 0.02);
        imp = myRight * ( -slideSpeed * carMass * actualGrip);
}

function slowVelocity()
{
        carRigidbody.AddForce(-flatVelo * 0.8);
}

function engineSound()
{
        audio.pitch = 0.30 + mySpeed * 0.025;
        if (mySpeed > 30)
        {
                audio.pitch = 0.25 + mySpeed * 0.015;
        }
        if (mySpeed > 40)
        {
                audio.pitch = 0.20 + mySpeed * 0.013;
        }
        if (mySpeed > 49)
        {
                audio.pitch = 0.15 + mySpeed * 0.011;
        }
        if ( audio.pitch > 2.0 )
        {
                audio.pitch = 2.0;
        }
}

function FixedUpdate()
{
        if(mySpeed < maxSpeed)
        {
                carRigidbody.AddForce( engineForce * Time.deltaTime);

                if (mySpeed > maxSpeedToTurn)
                {
                        carRigidbody.AddTorque ( turnVec * Time.deltaTime);
                }
                else if(mySpeed < maxSpeedToTurn)
                {
                        return;
                }
                carRigidbody.AddForce( imp * Time.deltaTime );
        }
}