Cars are the biggest piece of tech most of us own, but they're relatively conservative. Newer models may come with USB ports, Bluetooth, and touchscreens, but those have been elements for years. And the touchscreen experience isn't generally all that good, even with spiffy spoftware.

But significant enhancements are gradually working their way into our vehicles. A number of vehicles can detect when other cars are in their blind spots. Some can parallel park on their own. There are models in development that can drive limited distances without input from the driver. And, of course, there's Google's self-driving cars.

Then there is Volvo's idea to replace your key fob with your smartphone.

Instead of using a key to turn the ignition or verifying your presence inside a car using a fob, the vehicle will communicate with your phone over Bluetooth. A digital key tells the car that you're the owner.

The app gives you some added features over a physical key. You can send the digital key to family members or friends with compatible phones. People could potentially order rental vehicles and have keys arrive on their devices. They could then locate their rental car via GPS and hop in.

Volvo's existing On Call app already allows owners to check fuel, trip meters, and other dashboard information. Users can also lock doors, locate their vehicle on a map, and request roadside assistance.

Will you lose access to your vehicle when your phone dies? Yes. Volvo's director of new tech and services, Martin Rosenqvist, told the BBC, "If you lose your car key you need to go to a Volvo dealer - if you lose your phone you have to get a new phone. You can acquire a new app on a new phone."

So if you don't already have one, you might want to get a car charger. Volvo hopes to be the world's first car manufacturer to offer keyless cars when these models roll onto dealerships in 2017.

PRESS RELEASE