Nvm I'm getting it now

Any possibility on getting an easter egg hint? I've tried everything I could, seen a pap chart in the orange house, thought it was just the weapons that can be double pap. I blew up all the cars that could blow up, got the acidgat and zap guns, did buy c4 but it didn't show up in my invent...

Nice instakill shader, any plans on making the perk shaders BO3 or keeping them BO2 style?