feat: Better car creation

CarManagerV3/CarDetailsForm.cs

@@ -7,7 +7,7 @@ namespace CarManagerV3
     public partial class CarDetailsForm : Form
     {
 
-        Car car;
+        public Car car;
 
         public CarDetailsForm(Car car)
         {
@@ -21,7 +21,14 @@ namespace CarManagerV3
             nudPrice.Value = car.Price;
             tbxAge.Text = car.AgeString;
             pbxCarImage.Image = ImageManager.GetImage(car);
-            lblID.Text = $"ID: {car.Id}";
+            if (car.Id == 0)
+            {
+                lblID.Text = "New Car";
+            }
+            else
+            {
+                lblID.Text = $"ID: {car.Id}";
+            }
         }
 
         /// <summary>
@@ -118,7 +125,12 @@ namespace CarManagerV3
             msgbox.Show();
             await Task.Run(() =>
             {
-                StateManager.UpdateCar(car);
+                if(car.Id == 0) {
+                    car = StateManager.CreateCar(car.Make, car.Model, car.Year, car.Color, car.Mileage, car.Price);
+                }
+                else { 
+                    StateManager.UpdateCar(car);
+                }
                 Console.WriteLine("Saved car: " + car.Id);
             });
             Console.WriteLine("Car saved. " + car.Id);
@@ -133,6 +145,12 @@ namespace CarManagerV3
 
         private void btnDelete_Click(object sender, EventArgs e)
         {
+            if(car.Id == 0)
+            {
+                //just close form if car is not saved yet
+                this.Close();
+                return;
+            }
             //are you sure?
             var result = MessageBox.Show("Are you sure you want to delete this car?", "Delete Car", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);
             if (result == DialogResult.Yes)