Your car knows where you drive, how fast you go, your favorite destinations, and more. Pair your car with your phone, and it can access your contacts, your email, SMS history, favorite songs, and anything else stored on your phone. And while this data makes your car more convenient to use, it is far too valuable to remain private. “Car manufacturers benefit the most from the ‘data troves’ that cars carry around inside them,” Daivat Dholakia, director of operations at Force by Mojio, a GPS fleet tracking company, told Lifewire via email. “Many of them are invested in plans to monetize and sell this data to marketers and other third-party groups. The data that cars contain is simply immense, and manufacturers have every reason to use it for their own personal profit.”

The Good

Modern cars are computers on wheels. This brings all the convenience—and all the security concerns—of a regular computer, with lots of car-specific extras thrown into the mix. And like every security tradeoff, we are seduced by the perceived benefits of allowing our data to be harvested.  “The advantages mostly revolve around convenience,” Rex Freiberger, CEO of Gadget Review, told Lifewire via email. “If your car knows your preferences such as temperature control, things you like to listen to, places you like to go, it can pull those things up for you without assistance.” It goes further than that, though. Because your car has access to so much information, it can provide all kinds of neat services, like giving you maintenance notifications and accessing emergency contacts. But that data can be used for so much more, especially when it’s extracted, shared, and pooled with the data from millions of other drivers. 

The Bad

Cars can pull in around 25 gigabytes of data per hour, from up to 100 sensors. Insurance companies offer pay-as-you-drive plans, offering reduced premiums in exchange for access to data on acceleration, speed, and cornering. According to mobile provider Telekom, vehicle data is worth three times as much as the car business, itself. And the data doesn’t just come from your car. “One major risk is in connecting your vehicle and your smartphone; typically your phone died, you’re gonna get in the car, plug it into the USB,” John Peterson, editor of Safe Drive Gear, told Lifewire via email. “When you plug it in, it’s going to charge your phone, absolutely, and as soon as it powers up, it’s going to start sucking all your data.”

How to Protect Yourself From Your Car

Rule No. 1 of protecting yourself is to never, ever connect your phone to your car. “If privacy is a concern, the first step is to never connect Bluetooth, to begin with,” says Freiberger. “Your car will download and store all of your phone’s data—including your personal information—if you connect this. It’s something you agree to when joining a phone via Bluetooth.” “Take off or turn off any Bluetooth or GPS connection when you’re not in your car,” David Clelland, CEO of car-tracking company Infiniti Tracking, told Lifewire via email. “It’s best to never download any contacts to your car, too. It’ can be hard to avoid these, so always take extra measures to check and remove your data if you plan to sell your car.” USB is just as bad. You might think you’re just plugging your phone in to charge it, but you’re actually giving your car access to all the data on your phone.  “When you plug it in, it’s going to charge your phone, absolutely, and as soon as it powers up, it’s going to start sucking all your data,” Peterson told Lifewire via email.  The next step is to avoid giving your car any personal data. Don’t use your home address in the car’s GPS. Pick a nearby public landmark instead. And clear the GPS memory out regularly. If you can’t be bothered to do that, you should at least wipe it when you sell the car.  Unfortunately, there’s very little you can do to stop your car from collecting data about its own internal systems and where it goes. But you can at least keep your personal data out of its net.