An empty black SUV left running for more than an hour caused a bomb scare on the Upper West Side around noon Sunday.

The bomb squad rushed to the BMW parked in front of the Museum of Natural History on West 77th Street, smashing two windows before realizing it was harmless, a NYPD spokesman said.

The vehicle's windows were blacked out with a paisley pattern and the interior dashboard was blocked with a panel, raising the suspicions of police just a week after the Times Square bombing.

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The owner of the car, a BMW employee testing a 2011 SUV prototype, responded to the scene and eventually drove the vehicle away, said Tom Kowaleski, a BMW spokesman.

BMW adds the camouflage to prototypes to prevent competitors from steeling trademark material, Kowaleski said. As for why the car was left running, the employee apparently thought he had hit the off switch buried under the dashboard cover, but the super quiet engine didn’t let him know otherwise, he said.