Vehicles

Find a GPS tracker on a car in 60 seconds

Rental fleets have telematics built in — that's the company, and it's in the agreement you signed. What you're checking for is something a person added.

Top-down car diagram: check the OBD-II port, four wheel wells, bumper gaps, and inside — glovebox, under seats, floor mats, trunk

The check, in order

The OBD-II port. Under the dash on the driver's side, within about two feet of the steering column. A plug-in tracker sits right there because it's the easiest install and never needs a battery. Nothing should be in it. If something is, don't yank it — photograph it and call the rental company.
The four wheel wells. The number-one spot for magnetic trackers. Run your hand along the inner lip of each and feel for a box stuck to the metal. Ten seconds each, doable while you load the car.
The bumpers. Reach into the gap between the plastic bumper cover and the metal beam behind it, front and rear.
Inside. Glovebox, under both front seats, seat-back pockets, under the floor mats — including the trunk mat and spare-wheel well.

Find something you can't explain? Same rule as a room: leave it in place, photograph it, contact the rental company — and the police if you believe you're being followed personally. Don't drive to your hotel first.

The part that affects nearly everyone: the data you leave behind

Pair your phone with a rental's infotainment system and you can hand it your contacts, call log, sometimes messages, and your navigation history — which is to say, your home address. The FTC has warned about exactly this, and surveys of renters repeatedly find most people sync and fewer than half delete anything before returning the keys.

Don't pair at all if you can avoid it — use a 12V charger and a phone mount. (USB data ports can trigger a sync on some vehicles; a 12V adapter sidesteps it.)
If you pair, decline the contact/message sync. You can say no and still play music.
Before returning: delete your phone from the Bluetooth list, clear the navigation history and any saved home address, sign out of any streaming account. Two minutes, highest privacy return per minute of anything on this site.

Cover: The Traveler's Counter-Surveillance Field Manual

The Field Manual — PDF edition

Trackers on your person and in your bags are their own chapter. The complete system — every check on this site plus the ten-minute walkthrough, audio devices, your legal rights, and what to do if you find something. 47 printable pages, instant download, keep it on any device.

Get the Field Manual — $27

Prefer Kindle? $7.99 on Amazon.

Keep going

The 90-second room sweepFour steps, no gear — the check to run when you arrive. Find hidden cameras in an AirbnbWhere devices actually hide, and the rules hosts must follow. The flashlight trickThe one free method that catches a camera even when it is off. The two-way mirror testWhy the fingernail trick doesn't work — and what does. Do detector apps work?What a controlled lab study found when 11 apps met real hidden cameras. Unknown AirTag alert?What the tracker warnings can and cannot do, and the manual check. Found something? Do thisThe order matters: don't touch it, cover your sightlines, document.