Five years from now, if Mayor Bloomberg has his way, the area may well be a hotel and convention complex, but in the new film “Chop Shop,” which beings a two-week engagement today at Film Forum, the auto-repair alleys and drab lots that make up Willets Point are the world for 12-year-old Alejandro. Rahmin Bahrani’s follow-up to 2005’s “Man Push Cart” could be the object of preservation efforts as a historical document, but his neorealist record wobbles as filmed drama, with direction and scripting that’s at once shaky and insistent.

Young Alejandro (Alejandro Polanco), who goes by “Ale,” seems to live in a permanent state of hustle. He’s a runner and a tout at one of the chop shops, where he’s also allowed to sleep in a back room. But he also sells pirated DVDs and candy on the subway. “Excuse me, ladies and gentlemen, sorry for the interruption,” goes his familiar announcement to train riders, netting a few bucks to split with his partner.

The “Iron Triangle” of auto shops, which abuts Shea Stadium, is a traffic jam of a place: Cars roll down a puddle-filled strip past Ale and his competitors, against a backdrop of glass, metal, and rubber and under a perpetually harsh sun. The go-getter has the run of the place, literally — a signature shot is Ale running past corrugated garage doors, or darting between cars. He’s surprisingly buoyant for all this, and he clearly feels a sense of belonging. We join Ale shortly before his teenage sister comes to stay with him, after some sort of abuse trauma. The rapport between Isamar (Isamar Gonzales) and her brother is one of the brightest things about the movie, as is Mr. Bahrani’s silence on exactly how the two of them came to be living on their own, having fast-forwarded through childhood. Perhaps unsurprisingly, Ale is the stronger of the two, looking after his sister with little gestures like giving her a tip jar for the food van where she works. They also plan to buy and refurbish their own van.

There’s more to that tip jar than pocket change, though: It’s Ale’s caring attempt to steer his sister from her side job of turning tricks at a truck stop. Inevitably, he spies her in the cab of an 18-wheeler from a distance, and young Mr. Polanco handles the moment and its aftermath (fighting with a friend) well. But though her often slack face expresses a sense of broken-down defeat, Isamar’s part remains noticeably underwritten.

More generally, the confidence with which Mr. Bahrani plunges us into the milieu is paired with an odd anxiety when it comes to plot details and dialogue. Some of the most stilted lines and transitions aren’t even necessary to convey what’s happening, while frantically glued-together sequences sink the movie’s meandering final third. Similar weaknesses kept “Man Push Cart” from achieving its potential.

Mr. Bahrani’s hectic camera is sometimes more attuned to Ale than his screenplay is, including some lovely moments of repose at the sliding window to his bedroom and nerve-wracking shots stolen on an expressway. He also finds incidental ramshackle beauty in the boy’s environs. The plywood-lined room Ale shares with his sister glows with warmth, and the garages are a mottled array of peeled paint, dirt, and rust.

It’s puzzling that Mr. Bahrani repeats some of the mistakes he made in “Man Push Cart,” though that may reflect his overriding devotion to a sense of place and lifestyle. To be sure, the many precursors of “Chop Shop” in postwar European cinema and contemporary world cinema share some of the same compromises. But even so, the film should serve the energies of its moxie-filled young star as faithfully as it does the garages that are the movie’s inescapable horizon.

Through March 11 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).