I've seen those, too. We have lots of 'muracun made trucks here in the Heartland, too.
Still, those are Calvin ripoffs - neither true to him. My favorite Calvin is the poster where he says, "I'm not picking my nose, I'm pointing at my brain!" Sigh, that's the Calvin I remember - little boy through and through.
Forget Calvin. His dad was the man. Here's my favorite:
Calvin: Dad, will you explain the theory of relativity to me? I don't understand why time goes slower at great speed.
Dad: It's because you keep changing time zones. See if you fly to California, you gain three hours on a five-hour flight, right?
Dad: So if you go at the speed of light you gain more time, because it doesn't take as long to get there. Of course, the theory of relativity only works if you're going west.
Calvin: Gee, that's not what Mom said at all! She must be totally off her rocker.
Dad: Well, we men are better at abstract reasoning. Go tell her that.
Hee hee
SD