And, showtime! Many of you four-eyed (but wide-eyed), metal-mouthed (but hugely grinning) kids have now gotten up on your knees on the seats, insomuch as to ensure that the truck driver can clearly see you signaling frantically with flimsy arms, PULL THE HORN!! And most times, he'll happily oblige and make the truck give out a deafening bellow to everyone's delight, as kids scream and hi-five each other for having made this rolling beast come to life.
Aaaand... back to pressing your noses against the windows.
Hey, this still works.