Connecting your phone to a rental car's infotainment system for navigation or music can come with a privacy cost. According to experts cited in the article, pairing via Bluetooth can expose your name, contacts, and music-streaming logins to the next driver. Navigation and GPS history are especially sensitive because they can reveal where you stayed or worked.
The level of risk depends on the connection method. Bluetooth is considered more risky, while USB connections to Apple CarPlay or Android Auto are encrypted. However, rental car privacy policies often state that customers are responsible for data left in the vehicle. Avis, for example, says data may be stored in the infotainment center indefinitely by default and advises drivers to unpair their devices before returning the car.
To protect your data, the FCC recommends disconnecting the phone in Bluetooth settings, removing the vehicle from paired devices, and deleting your phone from the navigation system's history. A factory reset can wipe all traces, and the safest option is to avoid connecting the phone to the car altogether.