A tracker is one of the best ways to get a stolen car back — but on its own, it only tells you where the car has gone after it has already gone. If you want to actually stop the theft, not just chase it, the strongest setup pairs a tracker with an immobiliser. Our honest advice after 30+ years in the trade is simple: if you are fitting a tracker, you should always pair it with an immobiliser.
The three layers of vehicle security
Think of car security in three layers, from good to best:
- Layer one — the immobiliser (prevention). A CAN-bus immobiliser stops the engine starting without your PIN or tag. A relay attack, a cloned key or even your actual stolen key will not drive the car away.
- Layer two — the tracker (recovery). If a car is towed, winched onto a trailer or taken by force, a Thatcham-certificated tracker lets a 24/7 control room locate and recover it.
- The ultimate layer — both together. Prevention and recovery. Whether they are built into one system or fitted as two separate units, an immobiliser and a tracker working together is the most complete protection you can put on a vehicle.
Why the immobiliser should come first
A tracker is reactive — it helps after the theft. An immobiliser is proactive — it stops the theft happening at all. If you could only ever fit one, we would fit the immobiliser, because preventing a theft always beats chasing the car afterwards. But you shouldn’t have to choose: the two are far stronger together, and that is what we always recommend.
If you have a tracker, you should always have an immobiliser. The immobiliser keeps the car where it is; the tracker gets it back if it ever moves.
S5 or S7 — which tracker goes with your immobiliser?
This is where understanding the two Thatcham tracker tiers can actually save you money — we cover the difference in full in our guide to Thatcham-approved S5 and S7 trackers and what insurers require:
- A Thatcham S5 tracker includes automatic driver recognition. You carry an ID tag, and if the car moves without that tag present, the alarm is raised. That “no tag” layer is built into the tracker itself.
- A Thatcham S7 tracker is a straightforward GPS/GSM tracker without the driver-recognition tags — and it is cheaper.
So the right choice depends on where your “can’t be driven away” protection is coming from:
- If you want the tag-based, no-tag-no-start protection from the tracker itself, you need the S5 — the driver-recognition tags are part of it.
- If you are already fitting a proper immobiliser (with its own PIN or tag), the immobiliser is doing the drive-away prevention — and doing it more robustly than a tracker alert. In that case you don’t need to pay for the S5’s driver recognition. An S7 tracker covers the recovery side, and the immobiliser covers prevention.
In plain terms: an S7 plus a separate immobiliser is usually the smarter, better-value combination than an S5 relying on its tag. The car should never be drivable in the first place thanks to the immobiliser, so you get prevention from the immobiliser and recovery from the tracker — without paying twice for the same job.
Our recommendation
Whatever you drive, don’t rely on a tracker alone. Fit an immobiliser as your first line of defence, add a Thatcham tracker for recovery, and let us help you choose the right S5 or S7 pairing for your car and your budget. We fit both, and we’ll give you honest advice on the combination that genuinely makes sense — not just the most expensive one. Take a look at our current tracker packages, or compare our tracking systems and immobilisers.
Talk it through with us: call 03330 129 028 or WhatsApp us and we’ll recommend the right tracker-and-immobiliser setup for your vehicle.