A recent rash of luxury-car break-ins in DUMBO has locals wondering whether the bone-headed thieves flunked out of crime school.

Nine rides have been broken into in the last week — and one dense burglar made off with about $3 worth of coins but left behind a valuable digital camera.

Car owner Hugh Duthie discovered the stupid crook trick after his 1986 Mercedes-Benz was ransacked while parked on Adams Street.

The passenger-side window was smashed, and the glove box was looted, but the prowler ignored a fancy new sound system and a valuable pair of antique fireplace andirons.

“Nothing was gone but the change I use for meters in the ashtray,” Duthie said.

And while cleaning up the mess, Duthie was stunned to find a Fuji Finepix camera under one of the seats.