Physical security
Vehicle Security: The Complete Starting Guide
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Car thieves go after three things: the car itself, valuable parts like the catalytic converter, and whatever you left inside. Each one takes a different defense. Like your house, the goal isn’t to make the car impossible to steal. It’s to make it more trouble than the one parked next to it.
Where to start
- Keep your key fob in a signal blocking pouch at home.
- Never leave anything visible inside the car.
- Add a visible steering wheel lock.
- Hide a tracker in the car so you can find it if it’s taken.
- If your vehicle is a common target, protect the catalytic converter.
Stop the car being stolen
Block keyless relay and OBD theft
If your car unlocks and starts when the fob is nearby, thieves can use a relay device to pick up the fob’s signal from inside your house and pass it to the car. Others get inside and plug into the diagnostic (OBD) port under the dashboard to program a new key. A signal blocking (Faraday) pouch for the fob and a lock on the OBD port stop most of it.
Our guide to protecting your car from keyless relay theft covers how both attacks work, how to test a pouch and which car settings help.
What good looks like: a pouch that passes the test in that guide, and an OBD lock made for your make and model.
Use a steering wheel lock
A steering wheel lock is old school, but it’s visible from outside, and it adds time and noise to any theft. Most thieves will move on to an easier car.
Our pick
The Club Twin Hooks· Winner International
A twin hook steering wheel lock in bright yellow, so it’s easy to see from outside the car. The Club says it’s made from cro-moly steel with solid steel hooks, built to resist sawing, prying and hammering.
Downside: It opens to 14.4 inches at most, so measure your wheel first. It slows a thief and makes your car a less appealing target, but a determined one with tools can still get through it.
What good looks like: a bright, visible lock that fits your wheel and that you’ll actually put on every time.
Park smart
Park in a garage if you have one, and lock it. Otherwise, park in well lit spots with people and cameras around. At home, a camera covering the driveway helps, and our home security guide covers placement.
Protect the parts
Catalytic converters
Catalytic converters contain valuable metals, and a thief can cut one out from under a car in minutes. Some vehicles are targeted far more than others, often trucks and SUVs with high clearance and some hybrids. A metal shield or cage fitted over the converter makes it much slower to remove.
Some police departments and shops also offer to etch your VIN onto the converter, which makes it harder to sell.
Our pick
CatStrap catalytic converter shield· CatStrap
A low profile, layered steel shield that clamps and bonds over the converter and pipe, and is easy to install yourself. CatStrap says its hardened steel strips dull saw blades, so a quick cut turns into a long one.
Downside: CatStrap says it only comes off by cutting it, so any repair near the converter means buying a new one. It makes a theft slower, not impossible, and the cutting tests on its site are CatStrap's own. Check the compatibility chart against your exhaust before you buy.
What good looks like: a shield that fits your vehicle’s converter and exhaust, installed by a shop if you’re not comfortable doing it yourself.
Wheels
If your car has expensive wheels, locking lug nuts make them harder to take. Ones with a spinning collar are a little more secure, because a thief has a harder time hammering a socket or extractor over a collar that turns freely.
What good looks like: a set with a spinning collar that fits your wheels, with the key kept somewhere you’ll find it when you get a flat.
Protect what’s inside
Leave nothing visible
Most car break-ins are smash and grab. A bag, a jacket or a charging cable can be enough to get a window broken. Take it with you or put it out of sight before you park, not after you arrive.
Don’t keep house keys or remotes in the car
Don’t keep a garage door remote or spare house key in a car parked outside. A broken window then gets someone into your house too. Our guide to securing a garage door covers safer options.
Keep documents with your home address out of sight, so a thief doesn’t also learn where you live.
Watch and recover
Hide a tracker
A tracker hidden in the car gives you and the police a way to find it if it’s stolen. Small Bluetooth item trackers are cheap. Dedicated GPS trackers report location more reliably, usually with a subscription.
Check your car first, since some come with tracking built in, such as OnStar. Your owner’s manual or your car’s app will tell you what yours includes and whether you need an active plan.
What good looks like: a tracker you can hide well, with battery life or wiring that keeps it running.
Add a dashcam with parking mode
A dashcam records your driving, and with parking mode it also records when the car is bumped or approached while parked. That gives you evidence after a break-in, theft or hit and run.
Our pick
BlackVue ELITE 8 2CH dash cam· BlackVue
Front and rear 2K cameras with built-in GPS, plus three parking modes: power saving, motion detection and time-lapse. A memory card comes with it, and BlackVue gives it a 2 year warranty.
Downside: Parking mode needs the car's wiring (a hardwire cable is included) or an optional battery pack. Remote viewing needs a Wi-Fi connection or the optional LTE module, so out of the box it won't show you where a stolen car is. A dashcam is in plain view and a thief can pull it off, so it doesn't replace a hidden tracker.
What good looks like: a parking mode that’s actually powered while the car is off, and enough storage that footage isn’t overwritten too quickly.
If your car is stolen
- Call the police right away, with your plate number, VIN and the tracker’s location if you have one.
- Don’t try to recover the car yourself.
- Call your insurance company.
- Change any garage codes or locks if a remote or house key was in the car.