Passenger_car psc = new Passenger_car("BMW", 364, 300, 500);
            XmlSerializer formatter = new XmlSerializer(typeof(Passenger_car));

            using (FileStream fs = new FileStream("car.xml", FileMode.OpenOrCreate))
            {
                formatter.Serialize(fs, psc);
            }

            using (FileStream fs = new FileStream("car.xml", FileMode.OpenOrCreate))
            {
                psc = (Passenger_car)formatter.Deserialize(fs);

                Console.WriteLine("Марка: {0} --- Номер: {1} --- Скорость {2} --- Грузоподъёмность {3}", psc.stamp,psc.num,psc.speed,psc.carry);
            }