Agree.
When I was a kid, there were actually VW buses on the roads, and they were double punchbuggies. Two punches (to give) for the first lucky spotter! That’s where it ended though. No Jettas or Rabbits or even new Beetles. Calling a real, vintage Punchbuggy nowadays is a coup since there are so few of them. Maybe the reward should be more significant – like giving a stab in the eye with a fork, or a prolonged groping of your favorite body part.
Punchbuggy. I’ve heard of slugbug, but only recently. I’m 36, grew up in NJ.
Joe
Slug bug. Always, since early 70’s for me anyways, including my friends of East and Central Texas while I was ‘growing-up’ as well as relatives in several parts of Ohio that I visited occasionally.
A few years ago, my then ~8yr old daughter was sitting in back seat of car while we were going somewhere. She punched me on my shoulder and hollered “Slugbug” suddenly, having just spotted one nearby. Her face was beaming happiness since she had gotten to slug me for ‘good cause’. Since I had never told and/or taught her the ‘game’, it really surprised me, and she can’t remember where she heard of it (not mom either, fwiw). Kinda cool that it passed on to another generation…
I do suspect my loving wife/mother of the darling of teaching her though 
On my bus there was some rule where the punchbugging person had immunity to being punchbugged for a car of the same color. So if you saw a green Beetle and slugged the guy next to you, he wasn’t allowed to hit you when he saw a green beetle. (Red, blue, white, etc. were still good).
Something like that, anyway. I mostly remember trying to spot all all the colors out there, and being unable to find turquoise. There were turquoise Bugs, and people would start shouting, “Punchbuggy turquoise!”, but I always kept looking too late.
I’d like to retract my vote for Punchdub…
Punch-buggy here (grew up in the 80’s nad 90’s in VT.)
My sister still plays this and I never expect her too, for some reason. (she’s 33, I’m 27.) She or I’ll be driving somewhere and I’ll get hit in the arm, and she’ll say “punchbuggy [color], no punchbacks.”
But she cheats. She uses new beetles too. Excuse me? No, only the old-style beetles are allowed in my mind, despite VW’s ad campaign that might try to convince us otherwise.
I’ve never, ever heard of such a thing. Here on the dope is the first time I heard of it. I told my husband about it, and he had never heard of it as well.
“Slug Bug Blue!” [punch hard enough to crack a humerus]
Never heard “Punch Buggy” and definitely not “Punch Dub”, which to me just sounds like VW’s marketing attempt at making the game work across all their vehicles, rather than be specific with just the Beetle.
Everybody knows one?
Slug Bug Blue
Every garden grows one?
Punchbuggy or punch-a-bug.