What is the diamond shape on the BMW key?

[Jess]

On the BMW 5 Series key, the diamond-shaped button needs to be pressed and held when used. This button serves as a vehicle locator function—when you can't find your car, you can press and hold this button. The usage methods of other buttons on the BMW key are as follows: Closing windows after turning off the engine: Press and hold the lock button on the remote key to close the windows. Locating the car in a parking lot: Some car keys have a dedicated vehicle locator button, while others require pressing the lock button twice (or even more times). The vehicle will then emit a very loud honk and flash its hazard lights to indicate its location, helping the owner quickly find their car in crowded areas.