Hi. I knew this was a problem before I received my Santa Fe. I had driven at least 5 or 6 SF's before purchasing one. The problem showed up on about half of them. When I took delivery, I purposely checked the AC vent controls to make sure the vents didn't turn when putting the fans on high. In my case the vents stayed tight, and I accepted the SF. No problem with this since. I think that you would need to bring this back to dealership and complain like hell until they replace either the vents or the entire dash board.AC direction is important. If you cant control it, you will end up with a stiff neck or a very cold hand, etc.