PORTSMOUTH, Va. (WAVY) — It sounds like an easy task. Don’t want your car stolen? Lock the doors and don’t leave your keys in the car.

But for push-to-start cars, it may not be enough.

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Relay devices have been around for years, but now they’re being used to steal push-to-start cars by amplifying your key fob signal.

“Somebody within so many meters of it will have this device and it will relay the key fob’s signal to the device in the car so the car thinks that key fob is next to it and it unlocks it,” said Scott Gibson, head of Computer and Information Science at ECPI University.

Gibson tells 10 On Your Side the device was first used in Europe and in recent years has gained popularity in the U.S. It’s even been used here in Hampton Roads in the midst of a record summer of car thefts.

“Typically these types of attacks happen in residential areas where a lot of people have their keys hanging by the door or in the kitchen, an apartment community or townhouse community where keys are typically closer to where a car is parked,” Gibson explained.

Without a relay device, a person can typically unlock their car from about 30 feet away. With a relay device, the signal can be amplified anywhere from 100 to 300 feet.

“They can open your car and within 30 seconds to two minutes be out of your driveway with your vehicle,” Gibson stated.

Additionally, relay devices aren’t difficult to get ahold of.

“You could find these devices online probably between $80 and $150,” Gibson said.

Gibson tells 10 On Your Side to put extra safety measures in place if you have a push-to-start car.

“You’ve got to treat it no different and protect it no different than you would another electronic device like your cell phone. It’s a computer. Smart vehicles are computers. They are connected,” Gibson explained.

The best way to protect yourself if you have a key fob is to get a special pouch or bag like a Faraday bag that blocks your fob’s signal and prevents your car from being stolen.