Back in the first beta of iOS 13.4, the final version of which is already available for download to all users, they found a mention of the CarKey function, judging by the description of which your iPhone and Apple Watch can become keys to car doors:
MacRumors publishes screenshots of Twitter user under the nickname Donglebookproconfirming early rumors. What is known for sure: the electronic keys to the car will be stored in the Wallet application, and you can unlock the car doors without additional confirmation with a password or Face ID.
So, to unlock the doors, you need to double-click the side button and bring the smartphone or Apple Watch to the door of the car where the NFC tag is located. “Express mode” allows you not to use Face ID or password for authentication, which in theory will unlock the car door even with a discharged iPhone.
Also through the Wallet application it will be possible to open the trunk and control the ignition. Judging by the screenshot, very soon the new feature will become available to owners of BMW cars. When the official announcement will take place and which cars will support Apple CarKey is unknown.