There was a time when all you needed to use your car was a key. On older vehicles it was a traditional metal key, on more recent ones it had some kind of RFID chip for the immobilizer. As vehicles have become more and more computers on wheels though, the key has disappeared in favor of an electronic key using RF, and in many cases a smartphone application. It’s even used as a selling point: “Look how amazing our car is, you open it with an app!”
This is a companion discussion topic for the original entry at https://hackaday.com/2024/03/07/older-nissan-leafs-lose-their-app-are-they-the-first-of-many/