看到个委托事件问题

问题大致上就是：加速，减速两个功能，速度达到设定值就减速

class Program
    {
        static void Main(string[] args)
        {
            CarEven car = new CarEven();
            car.MaxSpeed = 180;
            UpSpeed up = new UpSpeed(car);
            DownSpeed down = new DownSpeed(car);
            for(int i=0;i<205;i++){
                car.Speed();
            }
            Console.ReadLine();
        }
    }
    //速度
    public delegate void SpeedEventHandler();

    public class CarEven{
        //速度事件
        public event SpeedEventHandler SpeedEvent;
        public int CurrSpeed { get; set; }
        public int MaxSpeed { get; set; }

        public CarEven()
        {
            CurrSpeed = 0;
        }

        public void Speed()
        {
            SpeedEvent();
        }
    }

    public class UpSpeed{
        CarEven car;
        public UpSpeed(CarEven car)
        {
            this.car = car;
            car.SpeedEvent +=new SpeedEventHandler(car_SpeedEvent); // 订阅事件
        }
        void car_SpeedEvent()
        {
            if (car.CurrSpeed < car.MaxSpeed)
            {
                Console.WriteLine("踩下油门，当前速度：{0}", car.CurrSpeed);
                car.CurrSpeed++;
            }
        }
    }

    public class DownSpeed{
        CarEven car;
        public DownSpeed(CarEven car)
        {
            this.car = car;
            car.SpeedEvent +=new SpeedEventHandler(car_SpeedEvent); // 订阅事件
        }
        void car_SpeedEvent()
        {
            if (car.CurrSpeed >= car.MaxSpeed)
            {
                Console.WriteLine("踩下刹车，当前速度：{0}", car.CurrSpeed);
                car.CurrSpeed = car.CurrSpeed - 10;
            }
        }
    }

一直没搞懂委托，最近打算弄懂它，不知道这样写对不对