This simple mod allows C4 to stick on AI. The code for sticking C4 to players, AI, and other objects was already coded in, but it was disabled in the final build. All I did was change a couple true/false around in one of the cpp files in the source code. Because of how it is coded, C4 only sticks to the chest. And it's pretty finicky about when it wants to stick. But it's very satisfying when it does stick.
So go sneak into a Korean outpost, stick some C4 to someone, then sneak out, and BOOM!