Below are technologies to eavesdrop on a vehicle without using a tracking device or listening device.

Concierge service (such as OnStar): Cellular connection is used to provide emergency assistance and concierge services.

Diagnostic port: Used by mechanics to diagnose problems, used by states to monitor emissions equipment. Some insurance companies offer discounts to drivers who voluntarily plug in devices, which send data back to the insurance company.

Driver camera: Driver-assist systems may use a camera to make sure you’re paying attention. The camera can detect drowsiness and distraction.

EDR (Electronic Data Recorder): Investigators use information stored on the EDR to determine what happened in the final seconds before a crash. [Related: How your car’s hidden ‘black box’ is helping Maine police — and creating privacy concerns]

Electronic toll collection (EZ Pass): Transponders create a record of your travel through toll barriers.

GPS: Location data can help you get around and navigate; the information is valuable to advertisers and police.

Infotainment/Smartphone/Bluetooth: A smartphone can be synced with a vehicle and upload contact, texts, and calls. Delete if you have a shared or rental car.

Obstacle detection: Vehicles use cameras and radar for automatic braking and forward-collision warning. Some car makers send the data back to manufacturers.

Onboard processors: Processors control engine timing and anti-lock brakes.

Telematics modem: Some car makers receive a data feed from your car’s computer with information like what’s on EDR or diagnostic port.

Tire pressure sensor: Monitors tire air pressure and transmits the information via low-frequency radio to on-board computer.