private void saveAllButton_Click(object sender, EventArgs e)
 {
     if (saveToLoadFromDialog.ShowDialog() == DialogResult.OK)
     {
         ChosenSerializer.Serialize(_cars, saveToLoadFromDialog.FileName);
     }
 }
 private void loadFromButton_Click(object sender, EventArgs e)
 {
     if (saveToLoadFromDialog.ShowDialog() == DialogResult.OK)
     {
         _cars = ChosenSerializer.Deserialize <List <Car> >(saveToLoadFromDialog.FileName);
         RefreshCarsDataSource();
     }
 }