Simple car movement

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;

public class CWheel
{
    public CWheel(Transform wheel, Boolean frontWheels)
    {
        Self = wheel;
        Visual = Self.Find("WheelGraphic");
        Collider = Self.gameObject.GetComponent<WheelCollider>();
        IsFrontWheel = frontWheels;
    }

    public void PerformUpdate(float forwardThrust, float currentSteer)
    {
        // Set torque on the rear wheels
        if (!IsFrontWheel)
            Collider.motorTorque = forwardThrust;

        // Rotate front wheels
        if (IsFrontWheel)
        {
            Quaternion steerRot = Quaternion.Euler(0, currentSteer, 0);
            Self.localRotation = steerRot;
        }

        // Perform wheel graphics update
        float rps = Collider.rpm / 60.0f;
        float angle = 360 * rps * Time.fixedDeltaTime;
        Visual.Rotate(-Vector3.up * angle);
    }

    public Transform Self;
    public Transform Visual;
    public WheelCollider Collider;
    public Boolean IsFrontWheel;

}


public class TheCarEngine : MonoBehaviour
{

    public float EnginePower = 50;
    public float MaxSteerAngle = 30;

    public Transform WheelFL;
    public Transform WheelFR;
    public Transform WheelRL;
    public Transform WheelRR;

    public Transform CenterOfMass;
    public float ForceDown = 3;

    private float thrust = 0;
    private float steer = 0;

    private float angle = 0;


    private List<CWheel> Wheels = new List<CWheel>();

    // Use this for initialization
    void Start()
    {
        Boolean[] frontWheelsFlag = new Boolean[] { true, true, false, false };
        Transform[] wheelTransforms = new Transform[] { WheelFL, WheelFR, WheelRL, WheelRR };

        for (int i = 0; i < 4; i++)
            Wheels.Add(new CWheel(wheelTransforms[i], frontWheelsFlag[i]));

        rigidbody.centerOfMass = CenterOfMass.position;
    }

    // Update is called once per frame
    void Update()
    {
        ReadInput();
    }

    void ReadInput()
    {
        thrust = Input.GetAxis("Vertical");
        steer = Input.GetAxis("Horizontal");

    }

    void FixedUpdate()
    {
        var forwardThrust = thrust * EnginePower;
        float currentSteer = steer * MaxSteerAngle;

        foreach (CWheel wheel in Wheels)
            wheel.PerformUpdate(forwardThrust, currentSteer);

        // try to push down
        foreach (CWheel wheel in Wheels)
        {
            rigidbody.AddForceAtPosition(Vector3.down*ForceDown, wheel.Self.position, ForceMode.Force);
        }

    }

}