Compared to the 2012-2013 Model X prototypes (top), there is something odd about the rear spoiler area of the 2015 Model X mule sightings (bottom two). One of them appear as if with a raised piece beneath the rear window, the second seems to be without this piece but shows cavities under the white wrap, suggesting something was removed from there. Merely fitting prototype panels together or is there going to be something (so far unseen) in this area? One idea, of course, would be an auto-raising spoiler: Of course this could merely signify some static component not yet being there (a fixed spoiler?), or the area being a just work in progress.