Volvo is here at Mobile World Congress with Ericsson demoing off its new “Phone as Key” technology. We thought this would be the perfect opportunity to sneak inside the brand new Volvo S90 sedan, which is also on the show floor, so we stopped by to check it out.

The “Phone as Key” app, as you’ll see in our gallery and video, allows you to use your smartphone to unlock the car and even start it. There are plenty of practical applications for this, and Volvo said it’s going to trial it with rental car services — whereby someone can simply walk up to a car and, using their smartphone and a digital key from a car service, unlock the car and drive away. No more waiting at the rental car counter in the airport just to pick up the keys for a rental you’ve already paid for.

Of course, this may also one day apply to everyday life, since Volvo hopes to bring it to its new cars and consumers, too. The application lets you send a key to a friend or family member, should they need to use it, and allows you to ditch your physical key altogether. Our kids in the future may look back at car keys as a funny thing of the past. We’ll need smartphones that don’t die as often, though, so there will certainly be a few roadblocks along the way.

Check out the Volvo S90 Phone as Key demo above now.