A developer tool app called ‘Car Keys Tests’ has surfaced on the App Store.
The Car Key feature was launched two years ago with little fanfare. However, Apple is hoping that the adaptation will get broader due to improved testing capabilities. The appearance of the testing app might indicate that a wider rollout will happen soon.

The Car Keys Tests app gives manufacturers functions such as troubleshooting, validating, and testing Car Key to ensure that their vehicles can run wireless key entry without any issues. As per description, the Car Keys Tests app is only for MFi licensees and to validate performance and connection for certification.
Car Keys Tests is not officially listed in the App Store, but there is a direct link for users to view and download the app. Non-licensees will have no way to access the functionality as there is a log-in screen when the app opens.