MVC List Not Working as it should - asp.net

Question

So the issue that I am having is getting the correct db items to work in the search in the web page, for some reason it does not search all of the values from Vehicle_Make that exist in Vehicle_Details - Make_ID is the primary key of Vehicle_Make and it is a FK in Vehicle_Details.
What happens is, it shows all the items on the page in a list, but the search does not work when I search for any of those items.
public class MapController : Controller
{
private GoogleMapEntities db = new GoogleMapEntities();
// GET: Map
public ActionResult Index()
{
GoogleMapEntities GE = new GoogleMapEntities();
List<Vehicle_Details> vehList = db.Vehicle_Details.ToList();
GoogleMapViewModel GMviewmodel = new GoogleMapViewModel();
List<GoogleMapViewModel> GMviewmodelList = vehList.Select(x=> new GoogleMapViewModel {
Make_Name = x.Vehicle_Make.Make_Name,
Make_ID = x.Vehicle_Make.Make_ID,
User_ID = x.User.User_ID,
MapLat = x.User.MapLat,
MapLong = x.User.MapLong
// Dealer_name = x.User.Dealer_name
}).ToList();
return View(GMviewmodelList);
}
[HttpPost]
public ActionResult Search(string Location)
{
GoogleMapEntities GE = new GoogleMapEntities();
////SELECT Make_Name DATA FROM DB1
var result = GE.Vehicle_Make.Where(x => x.Make_Name.StartsWith(Location)).ToList();
var GetVeh = (from vd in db.Vehicle_Details
join vm in db.Vehicle_Make
on vd.Make_ID equals vm.Make_ID
join u in db.User
on vd.User_ID equals u.User_ID
select vm).ToList();
//SELECT ALL ELEMENTS FROM Veh Make TABLE THAT EXISTS ON Veh Details TABLE BASED ON EXISTING ID's
var resultFinal = (from e in result
where !(from m in GetVeh
select m.Make_ID).Contains(e.Make_ID)
select e
).ToList();
return Json(resultFinal, JsonRequestBehavior.AllowGet);
}
}
Another weird thing that happens is, if I add the "!" in the following code, it does return the vehicle makes that do not exist in the vehicle details table but without the "!", it does not search for the values that do exist in both tables.
var resultFinal = (from e in result
where !(from m in GetVeh
select m.Make_ID).Contains(e.Make_ID)
select e
).ToList();
Sample Data:
BMW exists in Vehicle_Make(Make_ID PK) and Vehicle_Details(Make_ID FK).
Vespa exists in Vehicle_Make but not in Vehicle_Details
If I search for BMW it does not work but if I search for Vespa or any vehicle that does not exist in the Vehicle_Details table, it will find those, but not the vehicles that exist in both tables.
Once I get the correct items that need to be searched for like BMW, it must match the Dealerships(Users table) and take the MapLat & MapLong from the "Users" table and then pin point them onto the map.
Vehicle_Details has (User_ID FK) which is the PK of the Users Table.
Basically, Vehicle_Details has Users and Vehicle_Make linked to it, while Users and Vehicle_Make do not have a link in them so therefore vehicle details is the link. Is this possible to make work for what I require?