The second-to-last stop on the 7 train is Shea Stadium and, in its shadow, a way station for ailing cars called Willets Point, known as the “Iron Triangle” to locals and anyone who’s saved $200 on a windshield. At Jamaica Auto Body Glass, you can find a guy named Rob, and if you talk to people near his shop, you might hear the story of a 12-year-old boy who worked for him, waving down customers with thin, bare arms, for $5 a car. They might also remember a small camera crew that followed the boy around as he worked, which must have been making some kind of documentary.

That would be one version of the truth. Rob did pay the boy who brought him cars. But the boy, Alejandro Polanco, wasn’t working for Rob. He was working for the guy running the camera.

The resulting dramatic film, “Chop Shop,” about an orphan who lives and works in the Iron Triangle, opens next Wednesday at Film Forum. The director, Ramin Bahrani, likes people to believe that something he has staged and shot has simply just happened. This is more complicated than it sounds: It means that everyone, including the actors, has a limited idea of what’s really occurring on the set. People working at Willets Point didn’t know that Alejandro is an actor. There was a script, but Alejandro never saw it. At times, he didn’t know what the other actors were told to do. There’s truth in his performance, because in a way he’s living it. There’s just no telling to what extent Mr. Bahrani has gotten into the boy’s head and made him live it.

Mr. Bahrani’s films are engineered to look like they’re not engineered. He wants to make “the film that the filmmaker seems to be absent from,” as he put it in a recent interview. “I like to have complete control of what’s happening. But I don’t want to interfere with what life may do and how it may come and go from a scene.” So the director imposes a certain, sometimes rigorous, set of conditions. Then he films how people react. Mr. Bahrani’s last film, 2006’s “Man Push Cart,” told the story of Ahmad (Ahmad Razvi), a Pakistani pushcart vendor on a Manhattan street corner. It is a powerfully humane film, and may make you look for Ahmad, or someone like him, in those shiny kitchen cells . The predawn rhythm of the city, the entire life of a man framed by chrome, pastry-lined walls — Mr. Bahrani didn’t make any of that up. He simply made Mr. Razvi haul that cart, work constantly on the set, give people rides home, and spend his own nights on the director’s couch. “I wouldn’t sleep,” Mr. Razvi said. “He wouldn’t let me sleep.” The actor slept for two or three hours a night for three weeks. Mr. Bahrani stuck his leading man and the cart in the middle of traffic while he filmed from three blocks away. “There’s trucks and cars flying right by me, left and right,” Mr. Razvi remembered. “And the truck behind me doesn’t know that there’s a guy in front of this cart and he’s pulling it!”

Mr. Razvi had never acted. He had worked in a pushcart, then run a pastry shop in Brooklyn. His character in “Man Push Cart” hardly speaks and never smiles. Mr. Bahrani let the man inspire the character, created the character, then went back to condition the man.

The filmmaker didn’t make up Willets Point, either, an asphalt and scrap-metal village crammed with auto repair shops. There are no sewers there, and no sidewalks. Life pours onto the street. There is no distinction between a place for cars and a place for people. A tire spinning down the road has Alejandro bobbing behind, pushing it with his effortless gait. Here he comes again with an enormous fender across his shoulders. In “Chop Shop,” Alejandro tries to build a life for himself and his 16-year-old sister, Isamar (Isamar Gonzales). He sets his sights on a run-down food truck, and he and Isamar work to buy it.

Neither Alejandro nor Ms. Gonzalez had acted before. During the eight months of pre-production, they rehearsed on camera until they forgot about the camera entirely. Soon, the people in Willets Point began to ignore the camera, too, assuming that Alejandro was simply coming to work and being filmed for a documentary. “I would film them, too,” Mr. Bahrani said, “so they would think they were part of it.”

With their intense practice, every scene in “Chop Shop” could be one continuous shot, assembled from anywhere between 20 and 50 takes. If Mr. Bahrani had the money, he would film entirely in sequence so his actors could live the film from beginning to end, over and over again.

“It doesn’t matter how I made it or what I did to the people or how many takes or how I tricked Alejandro,” Mr. Bahrani said. He sometimes gets an emphatic look behind his thin-framed glasses. “They should live it. Until it’s right.”

Mr. Bahrani, 32, is the son of Iranian parents and a native of Winston-Salem, N.C. He came to New York to study film theory at Columbia, then spent three years in Iran. For his first feature, “Strangers” (2000), he didn’t conduct the kind of rehearsals that he does now, and swore never to make that mistake again. Mr. Bahrani’s films are not, he says, “attention-driven cinema.” It’s an ironic statement because they are, in fact, completely attention-driven. “Man Push Cart” does nothing but pay attention to Ahmad’s face, his hands, his fatigue, and the sounds of night and day. It pays scrupulous attention to Ahmad’s attention.

“Chop Shop” depicts a world within a world. There’s Willets Point, and then there’s the Willets Point of Alejandro’s dreams. The burden of reality seems to rest lightly on his narrow shoulders. But at night, when the chop shops close, not much remains besides Alejandro. For all that he fills the screen, with the spring in his limbs, his smiles and silences, he’s a child on the periphery, microwaving popcorn for dinner, waiting for his sister to come home. That’s just how it would be. His is a true story that just happens not to have taken place.