Is Your Car Vulnerable?
The easiest way to find out is with a simple test.
Walk up to your car with the key in your pocket and touch the door handle without pressing any buttons on the key fob.
If the vehicle unlocks automatically, it uses Passive Keyless Entry (PKE) and is potentially vulnerable to relay theft.
Keyless entry is now common on many vehicles built from around 2015 onwards, including family hatchbacks, SUVs and premium models. If you're unsure whether your vehicle has the feature, check your owner's manual or look for terms such as Keyless Entry, Comfort Access, Smart Entry, or Passive Entry.
The Best Ways to Prevent Relay Theft
1. Ghost Immobiliser
Effectiveness: ★★★★★
Typical Cost: £400–£600 (installed)
A Ghost immobiliser is widely regarded as one of the most effective anti-theft devices available.
Unlike factory security systems, it requires the driver to enter a unique PIN using existing buttons inside the vehicle before the engine will start.
Even if thieves successfully carry out a relay attack or clone your key, they won't be able to drive the vehicle away without the correct PIN.
Best for:
- Performance cars
- Prestige vehicles
- Keyless vehicles parked on driveways
- Long-term theft prevention
2. Faraday Pouch
Effectiveness: ★★★★☆
Typical Cost: £10–£40
A Faraday pouch blocks the radio signal emitted by your key fob, preventing relay devices from detecting it.
It's one of the cheapest and simplest security upgrades available, but quality varies considerably.
Always test a new pouch by placing the key inside, sealing it completely and attempting to unlock your car. If the doors still open, the pouch isn't providing adequate protection.
3. Signal-Blocking Key Box
Effectiveness: ★★★★☆
Typical Cost: £20–£60
A signal-blocking key box performs the same job as a Faraday pouch but offers a convenient place to store keys when you're at home.
Look for products specifically designed to block radio frequencies rather than decorative key boxes, which provide little or no protection.
4. Steering Wheel Lock
Effectiveness: ★★★☆☆
Typical Cost: £70–£180
Although mechanical steering locks have been around for decades, they remain an excellent visual deterrent.
Professional thieves generally look for the quickest target available. A visible steering lock increases the time and effort required, making many criminals move on to an easier vehicle.
5. OBD Port Lock
Effectiveness: ★★★☆☆
Typical Cost: £50–£150
Many organised thefts involve programming a new key through the vehicle's onboard diagnostic (OBD) port.
An OBD port lock helps prevent access to this connection, making it much more difficult for criminals to clone or programme replacement keys.
6. Vehicle Tracker
Effectiveness: ★★★☆☆ (Prevention)
★★★★★ (Recovery)
A tracker won't stop your car being stolen, but it can significantly improve the chances of recovering it.
Many modern systems provide:
- Live GPS tracking
- Instant theft alerts
- Geofencing
- 24/7 monitoring
- Police-supported recovery services
Trackers are particularly valuable for high-value and performance vehicles.
7. Software Updates
Effectiveness: ★★☆☆☆
Typical Cost: Usually free
Some manufacturers have introduced software updates that reduce the vulnerability of keyless systems.
While these updates may improve security, they shouldn't be relied upon as your only defence against relay theft.
Check with your dealership to see whether updates are available for your vehicle.
Why Layered Security Works Best
No single anti-theft device can guarantee complete protection.
The most effective strategy is to combine multiple layers of security, making your vehicle a far less attractive target than others nearby.
A strong security setup might include:
- A Faraday pouch or signal-blocking key box
- A Ghost immobiliser
- A steering wheel lock
- An OBD port lock
- A GPS tracker
Each additional layer increases the time, effort and risk for thieves, who will often abandon a vehicle if it's too difficult to steal.
Test Your Security Regularly
Even the best security products should be checked from time to time.
Testing a Faraday Pouch or Key Box
- Place your key inside and ensure it's fully sealed.
- Stand next to your vehicle.
- Touch the door handle.
If the car unlocks, the signal is still escaping and the product should be replaced.
If the vehicle remains locked, the signal is being successfully blocked.
Testing a Ghost Immobiliser
After installation, make sure:
- Your PIN sequence works correctly.
- Every authorised driver knows how to use it.
- The emergency override code is stored securely away from the vehicle.
Regular testing ensures your security system will work exactly as expected if it's ever needed.
Final Thoughts
Relay theft continues to be one of the most common methods used to steal modern vehicles, but it's also one of the easiest threats to defend against with the right precautions.
Simple measures such as a quality Faraday pouch can dramatically reduce your risk, while a Ghost immobiliser provides one of the strongest barriers against thieves driving your vehicle away. Adding visible deterrents like a steering wheel lock and recovery tools such as a GPS tracker creates multiple layers of protection that organised criminals are far less likely to overcome.