With all the censorship in today's popular culture, I actually believe it is quite hard to produce a film that could be considered "subversive" in the true meaning of the word. In my opinion, to successfully subvert the MPAA, the film would either have to be independently distributed, leading to an extremely small audience, or somehow produce a sensation for the viewer that is much more obscene or "adult oriented" than the actual visuals / audio would imply. Barring a technique like the one alluded to in the movie Fight Club, where he cuts frames of pornography into the middle of feature films, subversion is not possible. However, my opinion aside, I feel it is much more likely that subversive films would appear with relation to violence, as opposed to sex. There are very few physical acts of violence that have yet to be portrayed in some shape or form on the movie screen. Sex, on the other hand, is still a guaranteed "R" rating, minimum, with the more obscene movies (the obvious example being the small subsection of movies considered pornography) garnering the most extreme of ratings... something you don't see with violent movies.