You just reminded me of a similar long-forgotten game. We called it "bury the cows" and played it the same as you except for when you drove by a cemetery the kids on that side of the car "lost all their cows" and had to start counting all over. LOL! Thanks for the memories!
Our grandkids played some kind of a game where the first one to spot a VW yelled "punch buggy" and hit the kid sitting beside them. That game got out of hand quickly and had to be stopped.