6 ways your car can spy on you

Toll tags -- Instead of fumbling with change, you just drive through a toll booth and the payment is automatically deducted from your account. Of course, you're also letting someone know where you were at that exact moment and in which direction you were headed. Toll tags also provide valuable information about how well traffic is flowing. Computers can time how long it takes a car to travel from one toll booth to another or from one toll tag sensor to another.

Black boxes -- These boxes continuously record the car's speed as well as what the driver is doing with the steering wheel and brakes. The box has a short memory, though. The data is continuously overwritten every few seconds. In the event of a crash, the recording stops, preserving the few seconds of data just before and after the impact. Getting permission to download data from a car requires a court order, said Michigan personal injury attorney Dan Buckfire, but it's usually not hard to get one.

Cell phone navigation -- When you use your cell phone for turn-by-turn navigation there's a whole lot of data streaming in and out of your car. And that data can be very useful for monitoring traffic flow. Cell phone companies will send that data about vehicle speeds in various locations to companies that use it to provide real-time traffic information.

Telematics (OnStar) -- OnStar, the best known service, is linked to a GPS navigation system in your car even if your car isn't equipped with a computer navigation screen. The car shares data with the operators and computers that provide all those nifty services. But your exact location is usually only shared when you request some sort of service, like navigation or the name of an Italian restaurant nearby.

Insurance deals -- In the case of Progressive's Snapshot, a small device plugs into the car's diagnostics port. It doesn't record where you drive or even how fast. All it records is how many miles you drive, what time of day and how hard you step on the brakes. Frequent hard braking shows aggressive tendencies and that, Progressive's analysts have found, is an excellent predictor of crash risk. Drivers can agree to have their braking habits monitored for six months and, in return, they can qualify for a discount of up to 30%, Progressive says.

Spying on your teen -- Several simple devices now on the market allow you to track where, when and how fast your teen drives. Plugged into the car's vehicle diagnostics port, devices like the Tiwi, which also contains a GPS tracking device, allow parents to set limits on how much over the speed limit kids are allowed to drive and even define certain parts of town kids have to stay within. Parents can even be notified in real time when the limits are broken and a voice inside the car can remind the driver, too.

http://money.cnn.com/galleries/2011/technology/1109/gallery.autos_privacy/6.html