WASHINGTON, D.C.: Modern cars function like connected computers on wheels — and they're collecting large amounts of personal data. From GPS directions to seat belt sensors and onboard cameras, vehicles are constantly tracking where we go, how we drive, and even how we behave inside the car.

That has sparked growing concerns about privacy.

The Mozilla Foundation reviewed 25 car brands in 2023 and concluded that vehicles are the worst product category for privacy. Cars collect data from everyday actions like steering or unlocking doors, as well as from GPS systems, satellite radio, smartphone connections, cameras, and other sensors.

Telematics systems became common about 10 years ago, and data collection has expanded rapidly over the past 5 years. The biggest issue isn't just data collection — it's who receives that information. Insurers, marketers, and data brokers are among those who may gain access.

Earlier this year, the Federal Trade Commission banned General Motors from sharing driver data with consumer reporting agencies for 5 years, accusing the company of doing so without permission. Information such as nighttime driving or speeding was ultimately used by insurers to adjust rates.

Privacy experts say drivers should learn what their car collects. In many cases, you can enter a Vehicle Identification Number (VIN) online to see an automaker's privacy policy, including whether data is shared with insurers, brokers, or law enforcement. But dealerships don't always explain this clearly.

Data tracking usually starts as soon as you activate the car's systems, often by tapping "accept" on a dashboard screen. Some of this tracking can be turned off later. Experts recommend digging into your settings and revoking permissions you don't want.

Examples:

• Toyota drivers can decline "Master Data Consent" through the Toyota app.
• Ford owners can stop sharing some vehicle data via dashboard menus or the FordPass app.
• BMW offers options ranging from full data sharing to none, though limiting data can reduce features.

State privacy laws also give many U.S. drivers the right to restrict, delete, or opt out of data sharing. Requests can be made online, through automaker apps, or via the free Privacy4Cars service.

However, turning off certain tracking may disable helpful features such as navigation, roadside assistance, or remote access through smartphone apps. BMW says entirely disabling data transmission is like putting your car in "airplane mode."

If you trade in or sell a modern car, experts recommend performing a factory reset to erase stored data and disconnect the phone. It's also essential to notify the manufacturer about the ownership change so your driving data isn't wrongly linked to someone else.