Your car is on the drive, the key is on a hook in the hallway, and the doors are locked. Ten minutes later the space is empty and nobody has touched a window. That is keyless car theft.
This guide explains how the main attacks work, what each defence does and does not stop, and gives a layered checklist for this week. No single measure makes a car theft-proof. Layers make your car a harder, slower target, and thieves tend to move on to an easier one.
What is keyless car theft?
"Keyless car theft" is an umbrella term. It covers any theft where the thief gets into and drives away a car with keyless entry or a transponder key without breaking in the traditional way. Three methods account for most cases:
- Relay attacks, which trick the car into thinking your key is next to it.
- Key programming, where a thief plugs a device into the car's diagnostic port and creates a new working key.
- Signal jamming, which blocks the lock signal or hides a stolen car from its tracker.
According to Admiral, the UK's largest car insurer, between 60% and 70% of the cars stolen over a 12-month period were keyless models, as reported by Which?. Admiral notes it cannot always confirm the keyless system itself was used, because many stolen cars are never recovered.
How does a relay attack work?
A keyless car is constantly listening for a short-range radio signal from its key. When the key is close enough, the car unlocks and lets you start the engine. The system assumes that if the key can be heard, the key must be nearby.
A relay attack exploits that assumption. Two people work together, each carrying a device:
- One stands near your house, close to where the key is kept, and picks up the key's faint signal, even through a door or wall.
- That signal is passed on, effectively extended, to a second device held by the other person standing next to your car.
- The car hears what looks like your key and unlocks. Once inside, the same trick can satisfy the start-up check.
To the car, nothing is wrong. It has received a valid key signal. That is why a relay attack can be quiet, fast and leave no broken glass.
Key cloning and programming through the OBD port
Every modern car has an On-Board Diagnostics (OBD) port, normally under the dashboard, used by garages to read faults. It also lets a device talk to the car's electronics. A thief who gets inside, even briefly, can use specialist equipment to programme a blank key that the car accepts as genuine, then start the engine with it.
This is what people usually mean by "car key cloning", although the new key is often registered to the car rather than copied from yours. The result is the same: the car's own immobiliser sees a valid key, so it lets the engine run. A pouch around your original key does nothing against this method.
Signal jammers
A jammer is a device that floods a frequency with noise. Thieves use them in two ways. At the car park, a jammer can stop the lock command from reaching your car, so it looks locked when it is not. After a theft, a jammer can block the GPS or mobile signal of a tracker so the car cannot report where it is.
Always check the car has actually locked (indicators, lock sound, tug the handle), and if you fit a tracker, choose one that detects jamming.
Which cars are most at risk?
Any car with keyless entry or a transponder key can be targeted, and risk depends on the car's security design, how old its software is and how easily the OBD port can be reached. There is no honest one-line answer to "what is the hardest car to steal", because it varies by model, year and what has been added since.
We have deliberately not published a league table of models: "most stolen" lists change every year and only help when they come from a named source. Check your insurer's or the police's current guidance for your model.
Your layered protection checklist
Work down this list. Each item addresses a different part of the problem.
1. Put your keys in a Faraday pouch or box
A Faraday pouch is a signal-blocking bag. A key inside cannot be heard by a relay device. Use it every night, including the spare key, and keep both away from the front door, windows and the hallway hook.
How to test it: put the key in the pouch, close it fully, then stand next to the car and try to open the door. If the car unlocks, the pouch is not working. Test it again every few months, because pouches wear out at the seams and fold lines. A pouch you only half-close is no protection at all.
2. Turn off keyless entry if your car allows it
Some manufacturers let you disable the proximity unlock in the settings menu or with a button sequence on the fob, or have a sleep mode for the fob when it is not moved. Check your handbook or ask a franchised dealer. Not every car does.
3. Fit a steering wheel lock
It will not stop a determined thief, but a visible lock adds time and noise, and a thief with a choice often walks past.
4. Protect the OBD port
A lockable OBD port cover, or having the port relocated by a specialist, makes key programming slower and more awkward. Ask the installer what it does and does not protect on your specific car.
5. Park smartly
Use a locked garage if you have one, otherwise a well-lit spot. Keep valuables out of sight.
6. Keep the car's software up to date
Manufacturers sometimes release security updates for keyless systems. Ask your dealer at each service whether any are outstanding.
7. Fit an aftermarket immobiliser
The factory immobiliser trusts the key, and each attack above is a way of producing a key the car accepts. An aftermarket immobiliser adds a second check that does not depend on the key. Our explainer on what an engine immobiliser is covers how one works.
8. Add a tracker with tamper and jammer alerts
If the worst happens, a car tracker lets you and the police see where the car went. Features that matter: alerts for tow-away movement, power cut and jamming, and a backup battery. Our guide to whether car trackers can be jammed explains why jammer alerts matter.
How a fingerprint immobiliser defeats relay attacks and cloned keys
Relay attacks and cloned keys have one thing in common: they succeed in presenting the car with something that looks like a valid key. A fingerprint immobiliser asks a question the key cannot answer: is the person starting the car one of the drivers you registered?
With the Rubikas fingerprint module, the key alone does not start the car. If someone tries to start it with an unregistered fingerprint, the engine block triggers and you receive an alert. So a relayed signal, a programmed blank key or a stolen original key all hit the same wall. The reader supports up to 7,500 registered drivers.
The other half of the system is the remote engine block. From the Rubikas app you can block the engine yourself, and the block normally engages when the ignition is switched off, so a parked car cannot be started. If a jammer is used against the tracker, the device detects GPS and GSM jamming and alerts you.
If a fingerprint cannot be read, for example after a cut finger, the owner can temporarily disable fingerprint authentication from the app or web portal, and there is a valet mode for when a garage needs to drive the car.
To be honest about limits: nothing makes a car impossible to steal, and thieves can still tow one away. That is why the Rubikas tracker has a motion sensor that recognises when a car is lifted or towed, and why the system works best as one layer among several.
Rubikas packages (24-month rental, per car, including VAT):
- Rubi Protect: tracker plus engine block, £16.99 a month.
- Rubi Secure: tracker, engine block and fingerprint reader, £21.99 a month.
Installation is by certified installers anywhere in the UK, without cutting factory wiring. See the full details on our car immobiliser page.
What to do if your car is stolen
- If you see the theft in progress, call 999. Do not confront the thieves.
- Otherwise, report it on 101 (or online, depending on your force) and give the registration, make, model and colour. Ask for a crime reference number.
- If you have a tracker, tell the police straight away that the car is tracked and share the live location. Do not follow the car yourself.
- Call your insurer as soon as you have the crime reference number.
Frequently asked questions
How do I protect a keyless car from theft?
Use several layers. Store the key in a tested Faraday pouch away from doors, turn off keyless entry if the car allows it, lock the OBD port, use a visible steering wheel lock, keep the software updated and fit an aftermarket immobiliser and tracker. No single item is enough.
Which keyless cars are stolen most often in the UK?
It changes every year and depends on the source. Rather than rely on a list, check the latest figures from your insurer or the police for your make and model.
How can I prevent key fob cloning?
Cloning usually means a thief programming a new key through the OBD port, so a Faraday pouch alone will not stop it. Protect the OBD port, keep the car's software updated and add a second layer that does not rely on the key, such as a fingerprint immobiliser.
Does a Faraday pouch really work?
A good one does, if the key is fully sealed inside. Test it by closing the key in the pouch and trying to open the car from beside it. If the car still unlocks, replace the pouch.
Want a layer that does not depend on the key? Build your Rubikas bundle or call +44 7444 619588.