If you drive a modern car with keyless entry, you already know the feeling. You park up on your driveway, and somewhere in the back of your mind is the thought that a thief could be away with it in under a minute without ever touching your keys.
That worry is well founded. Keyless vehicle theft is one of the most common ways cars are stolen in the UK, and the counties we cover — Essex, Hertfordshire and North London — sit on exactly the road network that makes a stolen car easy to move quickly.
There is a lot of advice online about how to stop it. Most of it is fine as far as it goes. The problem is that almost all of it is written by people who cannot actually secure your car for you. This guide explains what the thieves are really doing, why the usual tips only take you part of the way, and what genuinely works.
How keyless car theft actually works
There are three methods worth understanding, because the defence against each one is different.
Relay attack
This is the one most people have heard of. Your key fob is constantly listening for your car. Two thieves work as a pair: one stands near your house with a device that picks up the fob’s signal through your wall, and relays it to a second device held by their partner at the car. The car believes the key is next to it, unlocks, and starts.
It takes seconds, it is silent, and it leaves no damage. Many owners only realise what happened when they see the driveway empty in the morning.
CAN injection
A newer and more serious method. Rather than chasing your key at all, the thief gains access to the vehicle’s wiring — often through a headlight unit, a wing mirror or another accessible point — and plugs a device directly into the car’s CAN bus network. That device sends the car a fake message telling it a valid key is present.
This matters, because a Faraday pouch does nothing at all against it. Your keys can be sitting in a metal box at the back of the house and the car will still start.
Key cloning and OBD programming
Once inside the vehicle, a thief can plug equipment into the OBD port and program a blank key to the car. From that point they have a working key and can come back for the vehicle whenever they choose.
Why the standard advice is not enough
Search for advice on keyless theft and you will be told to use a Faraday pouch, keep your keys away from the front door, turn off the fob’s wireless signal if your car supports it, and fit a steering wheel lock. None of that is bad advice, and we would encourage all of it. But be clear about what each measure does and does not do.
- A Faraday pouch defeats a relay attack only. It has no effect on CAN injection or key programming, and it only works if it is used every single time, by everyone in the household, including with the spare key.
- Keeping keys away from the front of the house reduces the chance of a successful relay, but relay equipment has improved and distance alone is not a guarantee.
- A steering wheel lock is a visible deterrent, which has real value — a thief looking for an easy target may move on. But a determined, equipped thief can defeat one, and it does nothing to stop the engine starting.
The honest summary is this: the standard advice makes your car a slightly less attractive target. It does not make it undriveable. If someone has specifically chosen your vehicle — and organised theft is increasingly to order, by make and model — you need something that stops the car moving and something that finds it if it does.
The three-layer approach
Proper vehicle security works in layers. Each layer does a different job, and each one covers a weakness in the others. This is how we approach every installation.
Layer one: an aftermarket immobiliser
This is the layer that actually stops the theft. A modern aftermarket immobiliser communicates with your vehicle’s CAN bus network and prevents the engine from starting — or the car from being driven away — unless the correct sequence is entered or the correct driver tag is present.
The important part is that it is not defeated by any of the three attacks above. It does not care whether the thief has relayed your key, injected the CAN bus or programmed a blank fob. Without the sequence or the tag, the car does not go anywhere.
There is no key fob to lose, nothing to remember to switch on, and no change to how you use your car day to day. It arms itself automatically. Systems of this type are typically operated either by a PIN sequence entered on buttons you already have in the vehicle, or by a small driver tag carried on your keyring. The Autowatch Ghost, Nitro Pro and Scorpion X all work on this principle, with differences in how they are operated, what they cost and what accreditation they carry. The Ghost II and the Nitro Pro are TASSA approved; the Scorpion X is not, so if your insurer specifies a TASSA-approved system, it is one of the first two.
We fit several brands rather than being tied to one, which means we recommend based on your vehicle and how you use it rather than on what we happen to stock. If you want to see the differences side by side, our immobiliser comparison sets them out.
Layer two: a Thatcham S5 or S7 tracker
An immobiliser stops the car being driven away. It cannot stop a vehicle being winched onto a flatbed, which is exactly what an organised team will do when they find they cannot start it. That is what the tracker layer is for.
Thatcham categories are the industry standard and the ones insurers recognise:
- Thatcham S7 is a tracking and recovery system, providing location monitoring and alerts if the vehicle moves without authorisation.
- Thatcham S5 adds driver recognition. The system knows whether an authorised driver tag is present, so if the car moves without one, that is treated as an unauthorised movement and escalated immediately. S5 is often the category insurers ask for on higher-value vehicles.
If your insurer has stipulated a category as a condition of cover, tell us before we quote and we will fit to that specification. You can read more about S5 tracker installation, S7 tracker installation and stolen vehicle recovery generally.
Layer three: a battery-powered backup tracker
This is the layer most installers do not offer, and the one we think makes the real difference on a high-value vehicle.
Organised thieves increasingly sweep a stolen vehicle for tracking devices before moving it any distance, and they know where a hardwired unit takes its power from. A self-contained battery-powered S7 tracker has no wiring to follow and no permanent power draw to trace, which makes it far harder to locate than a hardwired device.
We would not claim any device is impossible to find — anyone who tells you that is overselling. What we will say is that when a vehicle is swept and the obvious system is removed, a second independent unit that shares none of the same characteristics is often the thing that gets the car back.
As a matter of policy we do not publish photographs of installed units or describe where any device is fitted. That information only helps the wrong people.
What this looks like in practice
Not every car needs all three layers, and we will tell you honestly where the sensible stopping point is for your vehicle.
- For most family cars and vans, a quality immobiliser on its own is a significant step up and is often all that is needed.
- For vehicles that are known theft targets, or where an insurer requires it, an immobiliser plus a Thatcham S5 or S7 tracker is the standard combination — we offer this as a combined immobiliser and S5 tracker package.
- For high-value vehicles, or where a customer has already been targeted, we would add the battery-powered backup as a third layer.
Where we fit
We are a mobile installer, so we come to your home or workplace and fit on your driveway. Based in Cheshunt, we cover Essex, Hertfordshire and North London, including Romford, Brentwood, Chelmsford, Basildon, Epping, Chigwell, Loughton, Braintree, Hertford, Ware, Broxbourne, Hoddesdon, Potters Bar, St Albans, Watford, Enfield, Barnet, Edmonton and the surrounding areas.
Elite Car Security is a family-run business with over 30 years of experience, and a TASSA-approved installer — Member No. 0009. TASSA approval matters because it means our work is independently vetted, and insurers recognise it.
Common questions
Will fitting an immobiliser affect my warranty?
Fitted correctly, no. We install to a standard that does not interfere with manufacturer systems, and we do not cut into factory wiring unnecessarily.
Do I need to remember anything each time I drive?
No. The system arms itself when you leave the vehicle. Depending on which type you choose, you either carry a small tag or enter a short sequence using buttons already in the car.
Will my insurer reduce my premium?
Some do, some do not, and it varies by insurer and vehicle. What is more common is an insurer requiring a specific Thatcham category as a condition of covering a particular car at all. Always check with your insurer before you buy.
How long does installation take?
Most immobiliser installations take around two to three hours. Adding a tracker extends that. We will give you a realistic time when we book, and we call ahead on the day.
Talk to us
If you would like an honest recommendation for your vehicle, get in touch. We will ask what you drive, where it is parked overnight and what your insurer has asked for, and tell you what we would fit and why.
Call 03330 129 028 · WhatsApp 07506 555 717 · tony@elitecarsecurity.london