"What is a relay attack on a car?"

"A relay attack is a form of keyless car theft where two criminals work together. One stands near your house to amplify your key fob's signal, while the other stands by your car. The amplified signal tricks the car into thinking the key is present, unlocking the doors and allowing the engine to start — all without ever touching your key."

"How long does a relay attack take to steal a car?"

"A relay attack can be carried out in as little as 30 to 60 seconds. Because the attack works silently and requires no force, it often goes undetected until the car is already gone. UK police have recorded relay thefts taking less than 45 seconds from start to finish."

"What is the best protection against relay attacks in 2025?"

"The most effective protection against relay attacks is a CAN bus immobiliser, such as the TASSA-certified CarGuard, combined with a Faraday pouch for your key fob. The immobiliser prevents the engine from starting even if the key signal is relayed, while the Faraday pouch blocks the signal at source. Other measures include steering wheel locks, driveway cameras, and a secure metal key box."

"Do Faraday pouches stop relay attacks?"

"Yes, a Faraday pouch (also called a signal-blocking pouch or key signal blocker) prevents a relay attack by shielding your key fob's radio signal. However, they only work when your key is inside the pouch. For comprehensive protection, a Faraday pouch should be used alongside a CAN immobiliser."

Relay Attacks 2025: 7 Ways to Stop Keyless Car Theft

Introduction – The Surge in Keyless Theft

Home CCTV across the UK has captured ever‑faster relay thefts – some under 45 seconds. Understanding attacker tactics is the first step to beating them.

How a Relay Attack Works

Signal boosting: Thief #1 stands near your house and amplifies the smart‑key signal.
Signal relay: Thief #2 stands by the car with a second transceiver, fooling it into thinking the key is present.
Drive‑away: Once the engine starts, most cars won’t shut off mid‑drive, giving criminals time to swap plates and disable tracking.

7 Proven Defences (Ranked)

Rank	Defence	Effectiveness	Hassle
1	CAN‑bus Immobiliser	★★★★★	Low
2	RFID Deadlock / OBD‑Port Lock	★★★★☆	Medium
3	Motion‑sensing Faraday Pouch	★★★★☆	Low
4	Secure Drive‑Away Lockout	★★★☆☆	Medium
5	Steering Column Lock	★★★☆☆	Medium
6	Wheel Clamp	★★☆☆☆	High
7	CCTV & Smart Alarms	★★☆☆☆	Low

Case Study – BMW X5, London 2024

A customer installed a CarGuard CAN Immobiliser after two attempted relay attacks. Police reports confirm the device prevented further theft attempts, saving £68 000 in potential loss.

FAQ – Frequently Asked Questions

Does keeping my key in the fridge block the signal?

Sometimes, but condensation can damage the fob. A tested Faraday pouch is safer.

Can thieves jam the lock signal instead?

Yes. Always listen for the lock clunk and mirrors folding; consider walk‑away auto‑lock functions.

Stay One Step Ahead of Thieves

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