How relay theft beats the factory immobiliser in Leighton Buzzard

Every modern car on a Leighton Buzzard driveway already has an immobiliser. It has had one, by law, since the late nineties. That is the sentence people reach for when they decide they do not need another one fitted — and it is the sentence a relay thief is counting on.

The factory system was designed to stop a screwdriver in the ignition. It looks for a valid key, and if it finds one, it lets the engine start. Relay theft does not pick the lock or cut a wire. It presents that valid key.

Two people, two small radios. One stands at your front door, close to wherever the fob lives — a hall table, a coat pocket, a kitchen worktop. The key answers as it always does, because that is what a keyless fob is built to do: broadcast constantly, waiting for the car. That answer is boosted and passed to a second device beside the car. As far as the onboard system is concerned, the key is now in the driver's hand. The doors unlock. The start button works. The alarm stays silent because nothing, from the car's point of view, is wrong.

There is no broken glass and often no insurance payout either. Some policies treat a claim with no sign of forced entry as suspicious — which is precisely the evidence a relay attack does not leave.

A louder alarm does not help. Parking closer to the house can make it easier, because the key is nearer the front door. A signal-blocking pouch works, provided every key goes in it every single night, including the spare. One lapse is all it takes.

What actually stops it is a second immobiliser that does not live on the key. Ghost II and CAN Phantom sit on the car's own data network and refuse to let the engine fire until a sequence is entered on buttons the car already has — the steering wheel, the window switches, the climate controls. There is nothing to relay, because the sequence is in your head. There is no fob to clone and no LED for somebody to find. A thief who has already beaten the factory system finds a car that turns over and will not start, with no obvious reason why. Most walk away.

Fitting takes two to three hours on your own driveway in Leighton Buzzard, Linslade or the LU7 villages — evenings included, once you are home from work. Nothing is cut or drilled, so it can come out later without a trace. Send the registration and we will tell you which of the two suits the car, then give you a written price before any work starts.