When renting a car in a new city, you’re likely to sync your phone to its system to navigate around or play some tunes. But is connecting to car Bluetooth actually safe? Experts say this innocent move could cost you your privacy when the vehicle is returned.

That’s because linking your device may expose a variety of information to the next driver, including your name, stored contact information, and log-ins for music-streaming accounts. Phone and account names can reveal more than you might think: In 2015, a Baltimore man was able to track down the teens who stole his car via one of their phones, which had a name matching a public Instagram handle. Of all the data visible to a rental car, perhaps most sensitive is GPS and navigation history, which can give the next driver insight into where you were staying, or where you may work. There are ways to safely connect, but you have to be intentional before blasting your favorite tunes over the car system.

Whether you should pair your phone with a rental car depends on how you do so, and what you do after. Bluetooth is more risky, while using the USB allows you to connect to Apple CarPlay or Android Auto – both of which are encrypted, which means data transmitted between your device and the vehicle is protected from outside access. Typically car entertainment systems do not access your phone by default; instead, when connecting via Bluetooth you will see a pop-up on the vehicle or phone screen asking if you’d like to sync all contacts. By selecting “no” you can use the phone for music and navigation without sharing unnecessary information.

Most rental car privacy policies explicitly state that customers are responsible for any data transmitted when using the vehicle. Avis, for example, states that connected vehicles may automatically transmit data to the manufacturer, and that drivers who choose to sync devices to the system should be aware that data can be stored in the infotainment center indefinitely by default.

“Please always unpair your device and ensure that you take the necessary steps to remove your information from the system when you return the car at the end of your rental period,” the Avis policy says. “We are not responsible for any data that is left in the vehicle as a result of your use.”

Before returning a rental car, your first step for more safety is to disconnect from the car completely in your phone’s Bluetooth settings, and remove the vehicle from paired devices. Then, go directly into the navigation system and delete your phone from its history, the Federal Communications Commission suggests in its Consumer Guide on security for Bluetooth connections. If you used the in-car navigation without connecting your phone, you should go into the system to delete any history, including saved addresses.

For a more thorough option, many cars offer a factory reset process that will completely wipe away any trace of your time driving that can be found by looking at the vehicle manual. Of course, if you want to be extremely safe you can avoid connecting to the car at all and just navigate from your phone – you won’t get to DJ while you drive, but your data will remain untouched.