It's literally in the game though, those hidden features even have an "E3" Prefix.
The Worse, creator of the mod on Guru3d:
http://forums.guru3d.com/showthread.php?t=390114
Has made massive discoveries/improvements. He has discovered that almost all of the shaders and improvements seen in 2012 and 2013 are still in the game files, such as the e3 2012 explosions. For now he has managed to implement dynamic shadows from headlights, the increased rain density, increased NPC density, as well as 2012 e3 bloom and lens flare.
When he manages to unpack certain files, he will be able to activate everything, such as POMs, etc.