public partial class Form1 : Form
    {
        public Model1Container m;

        public Form1()
        {
            InitializeComponent();
            m = new Model1Container();
            bindingSource.DataSource = m.CarSet.ToList();
            dgv.DataSource = bindingSource;
        }
        private void bindingSource1_CurrentItemChanged(object sender, EventArgs e)
        {
            Car c = (Car)bindingSource.Current;
            tbCarCode.Text = c.Code;
        }
        private void btAddCar_Click(object sender, EventArgs e)
        {
            Car c = new Car();
            c.Code = tbCarCode.Text;
            bindingSource.Add(c);
            m.AddToCarSet(c);
        }
        private void btSaveChanges_Click(object sender, EventArgs e)
        {
            m.SaveChanges();
        }
  }
}