According to the U.S. Trademark and Patent Office’s recently published list, Apple has been awarded a patent titled “System and Method for Locating Mobile Devices in a Vehicle,” outlining how to locate devices such as iPhones in the confined space of a vehicle.

Note: Find My service at this stage does not use UWB to track the iPhone or iPad, but relies on GPS and other related assistive technologies to track, its positioning accuracy is not high, and it can not clearly inform the user of the exact location of the iPhone in the car.
In addition to the dialing method, Apple outlined in the patent a new way, mainly using multiple signal generators and sensors throughout the vehicle, by connecting the relevant sensors in the mobile device in series, used to detect where its location is.

A variety of signal generation techniques including infrared, Wi-Fi, Bluetooth and audio sound are outlined in the patent.
The patent states that mobile devices such as the iPhone can be accurately located in the car through the interaction between the signal generator and the sensor, using relevant algorithms to skim out obstacles such as seats in the car.
Apple also suggests that a similar job could be done using an inertial measurement unit (IMU). As the vehicle moves, the IMU continuously collects motion data, which is then collected and analyzed by the car’s computers.