If your X didn't come with those roof rails, then why not just order a set of Thule rack that are made for cars that doesn't have roof rails? It's much easier that way since you would not have to install the OEM roof rails in order to use those Thule racks. I'm 99% sure that you would have to drop the interior headliner to install the OEM roof rails, not to mention drill holes (I'm not a big fan of drilling into the body shell of my cars if it's not done at the factory, not to mention all the possibilities of rusts and leaks that might be involved if not done properly).