The Catapult Run, the biggest cross-country rallye of Equestria.
More than a mere race, it is an event of olympian spirit, in which the participation is half the competition. The other half, of course, is trying to avoid any Gallop Road Patrols who may disagree with the race's fun.
And yet another half is wacky hijinks, as our all-star cast dukes it out on the road, with many an odd detour for everypony.

Cars for no reason.
Inspired mostly by "The Cannonball Run".
Don't think about it too much.