SHERMAN OAKS ( ) — “Both of my cars are push.”

For Sherman Oaks resident Troy Byer, a traditional key ignition has become a thing of the past. In fact, keyless ignitions have become the new standard in many cars, allowing drivers to start their vehicles with the push of a button.

READ MORE: WeHo Follow-Home-Robbery Early Saturday Morning Under Investigation By Sheriff's Detectives

But there’s a growing problem with this popular feature: time and again, drivers are forgetting to push the button a second time and end up leaving the car running.

“I get in the car the next day, and it is still running, and I was like, ‘Oh my God. I left the car running’,” said Byer.

To date, there have been 18 deaths nationwide linked to keyless ignition mistakes.

It’s become such an issue that attorney Martis Alex filed a class-action lawsuit against 10 of the world’s largest automakers.

“Put your car in the garage, go into your home, never knowing that your engine is still running,” Alex said.

READ MORE: Judge Denies LA Firefighter's Union Request For Injunction Against City Vaccine Mandate Enforcement

While experts say it happens all the time because of today’s near-silent engines, the bigger problem with a running car is carbon-monoxide poisoning.

“There have been many instances … of people dying because of it,” according to Alex, who says there’s an easy solution and manufacturers should fix the problem.

“If we have an automatic shutoff [to] save you the inconvenience of a dead battery when you leave your headlights on, we can have an auto-shutoff on an engine to save your life,” he said.

Some automakers have taken that advice, adding a switch that turns the car off when a key is not detected. Others have added a beeping or other audio alarm to let drivers know when they have walked away from the vehicle without shutting off the ignition.

Byer says now that she knows about the problem, she’ll always doublecheck to make sure the car is off.

MORE NEWS: CHP Investigating 10 Freeway Shooting In Rosemead

“Of course, it would be a concern, and a legitimate concern,” she said.