Police say the 15-year-old was shot as he and the others were breaking into the car at 39-45 69th Place in Elmhurst around 2:30 a.m.
All three fled on a moped and crashed into a car driven by an off-duty police officer from New Jersey on 65th Street.
The three were held by the off-duty officer for responding police.
All three were taken to Elmhurst Hospital.
Charges are pending.
Burglary tools were found at the original scene, police said.
ALSO READ | Man who spotted subway shooting suspect Frank R. James, flagged down officers speaks out
* More Queens news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a News Tip