Logo: A young man buying a new car (i love images, Cultura, Getty Images)
Misplace your keys often? Better break yourself of that habit if your next auto has "smart key" technology.

A smart key isn't really a key, but rather a small device that transmits a code to the car's onboard computer. Your vehicle recognizes that it's you and starts up at the press of a button. This makes your car a lot harder to steal.

Unfortunately, it also provides "new opportunities for motorists to feel stupid," writes Matt Schmitz on the Cars.com blog, Kicking Tires.

Schmitz cites "forehead-slapping situations" like not knowing how to turn off the car quickly in an emergency, or forgetting to turn it off before getting out (which in a closed garage could lead to a potentially fatal buildup of carbon monoxide).

And if you lose your key, replacing it might cost as much as your monthly car payment.

"With a smart key, there's no avoiding the dealership for a replacement," writes Ronald Montoya in  a post on Edmunds.com.

Since there's no competition from ordinary locksmiths, the dealers can charge whatever they like. And they do: A quick search online shows prices ranging from $200 to $400 or more to buy and reprogram a lost key. Maybe a lot more, if you need to have the car towed to the dealer so that another key can be programmed.

Locked out

Here's another "d'oh!" moment: You lock the door and then realize that the smart key is on the passenger seat or fell out of your bag onto the floor of the car. Don't have a spare smart key on you? Hurry up and wait while someone brings it, or pay for a cab ride home to get it yourself.

That is, assuming you have a spare. A guy I know has misplaced one of the two keys provided when he bought the car. If he loses the other one, or locks himself out, well, d'oh!

The American Automobile Association reports having responded to 4 million lockouts in 2012. It's not known how many of those were smart-key vehicles. However, AAA spokeswoman Ginnie Pritchett points out that while the number of smart-key vehicles on the road has increased, the number of annual lockouts hasn't.

Another smart-key concern is that some of these vehicles can be turned off whether or not their automatic transmissions have been put into "park." This has caused injuries from vehicle rollaways, according to The New York Times. Auto theft and carbon monoxide poisoning are also possibilities.

Seven of 11 vehicles tested by Consumers Union (publisher of Consumer Reports) can be shut off while the gearshift is in "neutral" or "drive." The cars give both electronic and audible warnings that the transmission is not in "park," which led a CU spokesman to say it was not "too much of an issue." Of course, that assumes that the driver can hear an audible warning and/or pay attention to a visual one.

At some point smartphones could replace smart keys. Hyundai recently announced a design that will let drivers unlock and start cars with their phones, a technology that may be available by 2015.

'Motorists will need to adapt'
But what if you want to avoid smart technology altogether? Couldn't you just opt for brands that sell old-school metal keys?

For a while, maybe, but traditional car keys "will likely become obsolete" over time, according to AAA's John Nielsen. Better just to train ourselves to be more careful with the technology.

"Motorists will need to adapt with the technology to avoid the hassle and expense of smart key replacements," says Nielsen, director of automotive engineering and repair.

No matter what kind of key you use right now, Edmunds.com writer Montoya cautions against "tempting fate" by having just one key, smart or otherwise. "Consider this: If you lose all the keys to your car, you will need to get it towed to a dealership and it can potentially cost you close to $1,000 to replace the locks on your car."

That does not sound smart.

So be careful with the high-tech stuff, and if you're using metal keys get an extra couple of copies made: one to leave at home and one with a relative or trusted friend. Better make an extra one for the couch cushions to eat, too.

Do you use smart key technology? Any tips to share?

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