Punch Dub? WHAT???

What's up with VW and their commercials with the Punch Dub? Where in the world did this saying come from? PUNCH DUB? And when do you say it and punch someone? Whenever you see any VW what so ever. There goes a Jetta, PUNCH DUB! There goes a Beetle, PUNCH DUB! There goes a VW CC, PUNCH DUB! And what about the saying itself? When I was growing up, back in the 70's we would say SLUG BUG (you see how slug and bug rhyme? It kind of makes sense doesn't it?) whenever we saw a beetle and we would slug (hit) someone. Now as my kids got in there teens they started saying punch bug. I tried to correct them but to no avail. They still said punch bug. But now punch dub? I think this saying is just ridiculous and it's nothing like the game we used to play. I say let's get back to slug bug once again and cut all this punch dub stuff out.