Ok this is how the dealerships work here, and it shold be no different there. You can ask them to order a part that the do not have in stock. They go ahead and order it, and you tell them ou will pay for it when it gets in if it's the right part. The part has arrived and it's not the right one, they can return it, and it costs you nothing. If the part is the right one then you proceed to purchase it.