There's the button that unlocks the car's doors and the one that pops the trunk. And then, on some BMWs, the key fob has a button with a diamond on it.

BMW has gone all-in on digital car keys, with many of its latest vehicles offering the feature. But can you share these keys ...

Holding a Key Fob to Head Boosts How Far Away You Can Remotely Lock/Open a Car? And it's reportedly 100% safe.