Monologue from the backseat
"Grandpa and Cap, they know everything about cars. And engines. You could ask them the hardest question and they would just know it. I could ask them why this air freshener catches the smelly parts and they would just know. That is because they have lived a very long time and they know lots of things. Grown-ups? Just know some things. But old people know many things. That is why we should not break their bones. And Mom I want to tell you something: if asked them about engines they wouldn't not know a BIT."
There you have it: he thinks they are very wise, and old, and he does not want to break their bones (?!?).