So apparently all you need there is a silver tongue and a handful of c4. You can just walk up to the boss, Motorface or something, throw a charge on his lap, walk out and, well, you know the rest. That's overpowered. Not the explosion, or the spread of the damage, but the fact that you can actually go around tossing c4 left and right without a reaction from the npcs. And you can take out almost any non-aggressive npc like this.
I think that tossing a charge int the presence of an NPC should trigger some sort of reaction, like shooting you in the face and other gruesome things.
Perhaps in a later patch you'll fix it?