It seems like common sense: don't leave your car running and walk away.

But it appears far too many New Yorkers are doing just that.

Maksim Charnyy admits he was one of them. "Left the key, ran to the bathroom real quick, and came out — the car was leaving," he said.

With someone else behind the wheel of his 2006 Audi, speeding off from the BP gas station on Avenue U in Sheepshead Bay, Brooklyn. His two Chihuahuas and cellphone were inside the vehicle.

Charnyy said he tried to run behind the car. "Start screaming and yelling, 'Someone help me, call the police, call 911, my car was stolen!'"

The 39-year-old's car was found a few hours later, still running and his beloved dogs okay. But clearly, he's not alone.

The NYPD says so far this year, nearly 1,500 vehicles have been stolen because keys were left inside. That's an almost 20 percent increase from the same time last year, according to Deputy Inspector Jessica Corey.

"You think, 'It is just a minute, it is just a second, the car is going to be there when I come back,'" Corey said. "Unfortunately, not the case."

On November 27, a woman found out the hard way when she ran into a supermarket in Woodlawn in the Bronx. She left her SUV running with her 11-year-old son and elderly mother inside. The car was stolen with them in it. Police eventually stopped the vehicle on the Cross Bronx Expressway and arrested the alleged thief.

31 percent of vehicles were stolen because the keys were left in them, according to Corey, who's the commanding officer of the NYPD's Crime Prevention Division.

"A 100 percent preventable crime," she said. "Take your keys with you and lock your doors, and never leave your car running, not even for a minute."

The NYPD has even made a video warning drivers to take their keys and don't take chances. It shows a woman leaving her car running in front of a bodega she enters. The car is stolen.

"We like to have people feel that New York City is safe, but you still shouldn't leave your car running," Corey said.

Charnyy said says he's not going to make that mistake again.

"You have your keys with you and you lock the car," he said. "Forget everything else, try to clear your mind, make sure that you lock everything down. That's it."

And with the holiday season here, the NYPD isn't worried about only car thefts; it is also concerned with break-ins. Police officials say when you lock your vehicle door, don't leave gifts or other packages visible.