private void OnVehicleUpdated(VehiclesDetailViewModel source, Vehicle vehicle)
        {
            var vehicleInList = Vehicles.Single(v => v.Id == vehicle.Id);

            vehicleInList.Id     = vehicle.Id;
            vehicleInList.Year   = vehicle.Year;
            vehicleInList.Make   = vehicle.Make;
            vehicleInList.Model  = vehicle.Model;
            vehicleInList.Trim   = vehicle.Trim;
            vehicleInList.Engine = vehicle.Engine;
        }
 private void OnVehicleAdded(VehiclesDetailViewModel source, Vehicle vehicle)
 {
     Vehicles.Add(new VehicleViewModel(vehicle));
 }