Anyone see the 2005 Disney live-action
Sky High? It's about a high school for superheroes-in-development.
Action heroes very often require a cool ride. And of course what else would these teenagers ride in? A school bus: not just any school bus, but one (ca. 2000 IH/Carpenter) that transforms at the flip of a switch from regular ground bus to jet-powered flyer.
Better yet, when the main character has to save the day, he arrives aboard that bus!
Batman, Green Hornet, etc., eat your hearts out!