Ever had a passer-by flag you down and alert you to a soft tire on your car? You probably thanked the person and checked out your wheels.

Maybe it's time you questioned their sincerity.

Thieves in New York City have been posing as Good Samaritans, telling unsuspecting motorists they have a soft or flat tire. When the driver goes to inspect the wheel, they raid the cabin and steal valuables.

So far, ABC News reports, the criminals have robbed 16 drivers. Authorities believe at least three men are involved in the scam. Reports have come from Queens, Manhattan and Brooklyn, starting last summer. The most recent attack came last week.

ABC reports that in some of the incidents, the perpetrators wore construction worker's clothing and carried a can of Fix-A-Flat with them.