Dude, Where's My Car? (movie, 2000)

Jesse and Chester, two bumbling stoners, wake up one morning from a night of partying and cannot remember where they parked their car. They encounter a variety of people while looking for it, including their angry girlfriends, an angry street gang, a transexual stripper, a cult of alien seeking fanatics, and aliens in human form looking for a mystical device that could save or destroy the world.