Cars collect a lot of our personal data, and car companies disclose a lot of that data to third parties. It’s often unclear what’s being collected, and what's being shared and with whom. A recent New York Times article highlighted how data is shared by G.M. with insurance companies, sometimes without clear knowledge from the driver. If you're curious about what your car knows about you, you might be able to find out. In some cases, you may even be able to opt out of some of that sharing of data.