public ActionResult Create(Car car)
 {
     // TODO: Add insert logic here
     if (ModelState.IsValid)
     {
         _db.Cars.Add(car);
         _db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View();
 }
 public ActionResult Edit(Car car)
 {
     // TODO: Add update logic here
     if (ModelState.IsValid)
     {
         _db.Cars.Attach(car);
         _db.Entry<Car>(car).State = System.Data.Entity.EntityState.Modified;
         _db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View();
 }