In order to check the nuts holding the spoiler down, the 2 inner tail lights need to be removed. There's a torx screw at the top of the tail light you need to remove and pull the tail light out. Then reaching inside the hole towards the spoiler check to see if the mounting nuts are loose. There should be 4 I think. I would loosen them, being careful not to drop the nuts down inside the bumper cover, and see if anything is underneath where it mounts to the body. That's the on;y thing I could come up with. Hope that helps.