WASHINGTON — Before connecting a smartphone to that sleek rental car’s high-tech infotainment system, drivers should be aware of the personal data that they may unknowingly share.

Connected cars provide a lot of convenience, but syncing a phone with a vehicle may allow the car to download personal information such as contacts, addresses from GPS, text messages and possibly web browsing history.

The Federal Trade Commission wrote in a blog post that the information downloaded from the phone by a connected rental car may remain long after the car is returned. That means others may be able to access your information.

The FTC believes the safest bet is to fight the temptation and never connect a phone to a rental car. The best way to do that is to only use the cigarette lighter to charge it, since an on board USB plug could automatically transfer data once connected.

For drivers who choose to connect their phones to the car, the FTC recommends that you check the permissions the car receives when you allow it to connect to the phone. Only give the car permission to access the information you want it to access.

If you do end up connecting to the car’s system, don’t forget to delete your phone’s information. The task of deleting a phone from the car may require a few minutes with the instruction manual, but it is worth the time to remove your phone’s data from the vehicle.