Written and directed in just two months, this low-key comedy by Chilean filmmaker Sebastian Silva (The Maid) has a loose, casual vibe, but it never feels aimless. Cast against type, Michael Cera plays an obnoxious rich kid, obsessed with partying and drugs, who takes a road trip to a remote part of the country famed for its hallucinogenic cactus; accompanying him are three exceedingly tolerant Chilean friends (played by the director’s brothers) and an eccentric California hippie (Gaby Hoffmann) who calls herself Crystal Fairy and proves almost as irritating as Cera’s character. Silva based the story on a personal experience from his early 20s, which he realizes with vivid detail and wry, humane observation; the humor is sweet and lingers in the memory. In English and subtitled Spanish.