References to the new 'CarKey' feature have been found in iOS 13.4 Beta through 9to5Mac. This feature seems to allow users to use their iPhone or Apple Watch as NFC car keys.
iOS 13.4 refers to the "CarKey" API, which will make it possible to use the iPhone and Apple Pulse Watch to unlock, lock and start the car. According to the internal files of the system, users will be able to use CarKey in NFC-compatible cars, as they only need to have a device near the vehicle to use as a key.
CarKey will not require authentication with Face ID as it does in Express Transit mode. This means that your device can unlock your vehicle for up to five hours after your battery dies.
To use CarKey, place an iPhone or .pal watch on the reader. It will work automatically, without the need for a Face ID. You can change Express mode settings in Lettuce.
The pair will be via the Wallet app. You can place your iPhone on the NFC reader in a compatible vehicle for initial setup and then be available in the CarKey Wallet. After that, you can add the key to your Apple Palm clock. 9to5Mac also received a string indicating that users could share their key with others.
For more information visit 9to5Mac