Tayo is envious of the grown-up buses who can drive around until late and can sleep in until late in the morning. By chance, Tayo helps a grandmother car, Wizard car who turns out to be a wizard. She says she'll grant him one wish.
Tayo uses his wish to become a grown-up. Tayo is happy that he can now play until late at night. But the good feeling doesn't last long. Tayo realizes the responsibilities he must take on as a grown-up bus and begins to get exhausted.