In Roger Corman's GAS-S-S-S, Or It Became Necessary To Destroy The World In Order To Save It, the military releases a gas that kills everyone over the age of 25. The result? A bongo-bruising hippie dance party, and a movie you really need to be on hash to appreciate. What do you do when all the old farts are dead? Have a crazy rave party, with freaky shapes, at a drive-in theater... featuring Country Joe And The Fish!
Nooooo! Make it stop!
I love how in apocalyptic movies, the roads are always clogged with derelict cars. It never fails: