protected void Page_Load(object sender, EventArgs e)
        {
            var seat1   = new seat("Gray", "Leather");
            var seat2   = new seat();
            var engine1 = new engine();
            var engine2 = new engine(12, "high compression", "48 valve hi flow", "High lift stroker", "internal coil and HV ignition", "fuel injected");

            var car = new car(4, 5);

            car.addSeat(seat1);
            car.addSeat(seat2);
        }
 public void addSeat(seat seat)
 {
     seats.Add(seat);
 }