Keyless theft
Which car alarms actually stop keyless theft?
What an alarm can and cannot do against relay theft, which features matter, which Pandora systems have phone alerts and GPS, and when an immobiliser is better.
Short answer: against a car being driven away by relay theft, what works is something that refuses to let the car move without your tag or your code. That means an alarm system with a built in immobiliser released by a tag, or a dedicated immobiliser. A siren on its own does not stop a car that thinks the real key is sitting in the driver’s seat.
That is the honest version. The rest of this guide explains why, what to look for, and which of the systems we fit do what.
How keyless theft works
A keyless car unlocks and starts when it detects your key close by. Relay theft fools it. One thief stands near your front door with a device that picks up the key’s signal from inside the house, and passes it to a second device held next to the car. The car believes the key is present, so it opens and starts. Nothing is broken and nothing is forced. Our guide to relay theft goes through it step by step, and this one helps you work out whether your car is exposed.
This is why a lot of alarms fall short. If the car accepts the relayed signal as your key, an alarm that trusts the key has no reason to go off.
What actually matters
Something other than the key has the final say. This is the feature that matters most. On the Pandora systems we fit, the immobiliser is released by an encrypted Bluetooth tag in your pocket, not by your car key. A relayed or cloned key gets a thief into the car and no further, because the car is checking for the tag.
Immobilisation that ignores the key. Ask whether the system stops the engine running, not only whether it makes a noise. If it only sounds a siren, a thief with a working relay can still drive away while it sounds.
Alerts on your phone. A siren on a driveway at two in the morning is easy to sleep through. A system with a mobile connection can push an alert to your phone while somebody is still stood by the car, and some will ring you and text as well.
GPS tracking. It does not stop the theft, but it tells you where the car is and where it has been. That needs a SIM in the unit, which brings a running cost.
Thatcham approval, if your insurer asks for it. Some policies name an approved alarm or immobiliser. If yours does, check the exact wording before you choose. We explain what Thatcham approved means separately.
Alarms with phone alerts and GPS
These are the Pandora systems we fit that combine an immobiliser released by a tag, alerts to your phone from anywhere, and GPS tracking.
| Model | Alerts to your phone | GPS | Tag authorisation | Thatcham approved |
|---|---|---|---|---|
| Pandora Elite | Yes, over 4G | Yes, GPS and GLONASS | Yes, immobiliser tag | Yes, Category 1 (TSC250) |
| Pandora Smart Pro | Yes, over 4G, plus calls and texts | Yes | Yes, Bluetooth 5.0 tag | Yes |
| Pandora Smart | Yes, over 4G, plus calls and texts | Yes, GPS and GLONASS | Yes, Bluetooth 5.0 tag | No |
| Pandora Storm Plus | Yes, 4G push, calls or texts | Yes | Yes, Bluetooth tag | Yes, CAT 2 (TSC523) |
A few things the table does not show.
The Smart Pro is the approved one, the Smart is not. The Smart Pro comes with a siren as part of the system, and that siren is a large part of why it is Thatcham approved. The Smart does not come with one. If your insurer has asked for an approved alarm, the Smart will not satisfy it.
The Elite adds more on top. A two way OLED remote on long range radio, dual antennas, wifi positioning for underground car parks, and detection of relay attacks, key cloning and signal jammers. On most family cars the Smart Pro covers the same core job. We compare the two here.
The Storm Plus is not an alarm. It has no siren and no shock or tilt sensors. It is an immobiliser with tracking and alerts added, so it belongs in this table for keyless theft, but not if you want the car to make a noise.
There are options without a SIM. The Pandora Light Pro is a full alarm with a siren, a two way remote and an immobiliser tag, and the Pandora Mini BT is a compact system with a Bluetooth tag that runs from your original key. Neither has GPS or a mobile connection, so neither can reach you when you are away from the car. Both still stop a relayed key moving it, and there is nothing to pay monthly.
Other alarm brands exist, and some will do a similar job. We only describe what we fit, because those are the systems we can vouch for.
When an immobiliser is the better answer
If your real worry is waking up to an empty driveway, you may not need an alarm at all. A dedicated immobiliser does that one job, silently, with nothing for a thief to find.
Autowatch Ghost III. You enter a code on buttons the car already has, such as the steering wheel controls. Ghost III also accepts an authorised key-tag or your phone. Without authorisation the engine will not run, even with your genuine key. Autowatch do not state a Thatcham category for the Ghost III.
Pandora Microbot. About the size of a USB stick. You authorise it with a Bluetooth tag, a PIN on your steering wheel buttons, or the app. Depending on the car it can block the engine, the engine start, the automatic gearbox and the keyless system. It holds Thatcham CAT 2e approval, certificate TSC741.
What you give up. Neither is an alarm. No siren, no sensors and no alerts. If somebody takes your wheels or empties the boot, they will not notice. We compare the two immobilisers here, and set out an immobiliser against an alarm separately.
Choosing both. Some people want the car stopped and want to be told when something happens. Every alarm in the table above already has an immobiliser released by a tag. A separate immobiliser alongside an alarm does not link up with it; each does its own job. We will tell you whether that is worth doing on your car, and say so if it is not.
What about Faraday pouches?
A good pouch does block your key’s signal, and it is worth having, but it only works on the nights the key goes in it. Our Faraday pouch guide explains why we never treat one as the whole answer.
Fitting matters as much as the system
The first thing a thief looks for is the unit. A system hidden carefully beats a better one fitted somewhere obvious. That is most of what you are paying an installer for, and it is why we fit at your home or workplace rather than posting kit out.
Ask us about your car
Tell us the make, model and year, where the car sits overnight, and whether your insurer has asked for anything specific. We will tell you which system we would fit, whether an alarm, an immobiliser or a tracker suits you best, and which ones you do not need.