public void SaveCar(Car car)
{
string fullName = Path.Combine(_filePath, "OurCar.json");
string carContents = JsonConvert.SerializeObject(car);
File.WriteAllText(fullName, carContents);
}
void SaveCarFromForm()
{
var car = new Car();
car.Color = colorTextBox.Text;
car.Make = makeTextBox.Text;
car.Model = modelTextBox.Text;
int year;
if (int.TryParse(yearTextBox.Text, out year))
car.Year = year;
var service = new CarService();
service.SaveCar(car);
}