Implementation of C# Custom Generic Class

public class Car
    {
        public string PetName;
        public int Speed;
        public Car(string name, int currentSpeed)
        {
            PetName = name;
            Speed = currentSpeed;
        }
        public Car() { }
    }
    public class CarCollection<T> : IEnumerable<T> where T : Car
    {
        private List<T> Tcars = new List<T>();
//Add to
        public void AddCar(T t)
        {
            (t);
        }
//Get one of them
        public T GetCar(int pos)
        {
           return Tcars[pos];
        }
        public int Count()
        {
            return ;
        }
#region IEnumerable<T> Member
        public IEnumerator<T> GetEnumerator()
        {
            return ();
        }
        #endregion
#region IEnumerable Member
        ()
        {
            return ();
        }
        #endregion
    }