i made one of the SUVs an Opel Hungarian Police
All you need to do is take all these xml and vox files into the car folder inside the vehicle folder, inside the assets folder, inside the vehiclepack folder.
Before testing the mod, write the following things in the file named vehiclepack spawn after #cars:
assets/vehicle/car/O.H.P.xml : Hungarian Vehicles/Hungarian Police
Enjoy it :)