I built a car immobiliser from scratch — here is why the market was charging £499

I am not a marketer. I am a hardware and software engineer. I have been building electronics professionally for over a decade. When I decided to build a vehicle immobiliser, I did not start with a business plan. I started with a circuit board and a problem I could not stop thinking about.

What I am about to tell you is not marketing copy. It is the actual technical and commercial reality of how LockCar came to exist, what the products cost to produce, why I made the specific engineering decisions I made, and why I believe those decisions matter for anyone who owns a car worth protecting.

You can make up your own mind about whether any of it is worth your time. But it is all true, and it is all mine.

The problem I kept seeing

I had been watching the UK vehicle theft statistics for a while before I started building anything. The numbers had been rising sharply since 2015, and the method driving that increase was specific: relay attacks on keyless entry vehicles. According to DVLA data reported by What Car? in February 2026, 54,830 vehicles were stolen in 2025 alone, equating to 150 cars every single day, and that figure is still more than twice the number stolen a decade ago in 2015.

The market had a response to this: aftermarket immobilisers. The dominant product was the Ghost, which works by connecting to the vehicle’s CAN bus and requiring a button sequence before the engine will start. The installed price for a Ghost II is listed at £499 by the major national installer networks.

I understood the engineering behind this. I also understood its limitations. The CAN bus is the vehicle’s internal communication network. It was designed to carry signals between authorised manufacturer-fitted modules at precise timing intervals. Adding an unrecognised third-party device to this network is not a neutral act. It introduces variables that the manufacturer did not account for, and in a meaningful number of documented real-world cases, it causes ECU faults, dashboard errors, and diagnostic bills. I had seen this happen to other people’s vehicles before I built anything.

So I had a technical constraint I chose to impose on myself before I had a product at all. Whatever I built would use a physical relay to cut the engine circuit. Zero communication with the ECU network. Full stop.

What is actually inside one of these devices

I want to be clear about what I mean when I say I built this from scratch. I designed the PCB layout. I specified every component. I wrote the firmware that runs on the microcontroller. I wrote the Wi-Fi communication stack. I wrote the mobile app. I assembled the first units by hand.

This is not a reseller operation where I source a device from a manufacturer in Shenzhen, put a label on it, and sell it as a UK product. Every circuit board in a LockCar device was designed by me, in the UK, to solve a specific engineering problem.

The cost of making one and what the market charges for one

I want to be careful about what I claim here, because the cost of manufacturing a device involves a range of variables and I do not want to overstate anything. What I can tell you honestly is that the component cost of producing a LockCar immobiliser at the scale I am currently operating is a small fraction of what the market charges for comparable protection. This is not magic. It is the arithmetic of manufacturing versus reselling, and cutting out every layer of the distribution chain between the engineer who built it and the customer who buys it.

The price difference is not because the LockCar IC3ST is a worse product. On the metrics that matter most to car security — does it physically cut the engine circuit, does it do so without touching the ECU, does it arm and disarm hands-free without a PIN sequence — the IC3ST is a technically sounder product than a Ghost at £499. The IS357 adds a 5-metre proximity range and smartwatch support for £149. The ONE Plus adds 4G, live camera, GPS, and automatic night immobilisation for £199.

The price difference exists because I removed the distribution chain and its associated margins. When you buy from LockCar, the money goes to the person who designed it, built it, and will install it at your door. There is no other entity in the chain taking a cut.

Why I chose relay over CAN bus from the start

This is the engineering decision I am most often asked to justify. The CAN bus approach has genuine advantages: it is invisible to the driver, requires no physical circuit modification, and allows sophisticated interaction with vehicle electronics. Ghost built a significant market on these strengths.

My objection to CAN bus is not that it does not work. It is that it introduces a category of risk that a relay design eliminates entirely. Here is the technical argument:

A CAN bus immobiliser must sit on the vehicle’s internal network as an unrecognised module. The network was calibrated by the manufacturer for a specific set of authorised modules communicating in a specific pattern. The aftermarket device adds noise that the system was not designed to handle. In vehicles with tightly timed ECU networks — and modern European vehicles increasingly fall into this category — this interference can accumulate over time into genuine faults.

A relay immobiliser has no presence on the network at all. The 20A relay breaks or completes a physical circuit. The car’s electronics have no awareness of it. There is no signal to interfere with. There is no module the ECU needs to account for. From the vehicle’s diagnostic perspective, the relay immobiliser does not exist.

The relay approach also has a security advantage that became clear to me as I thought through the attack surface. A CAN bus device communicates on the same network that processes security-relevant commands. In theory, a sufficiently sophisticated CAN bus injection attack could target the immobiliser by sending commands that the bus device interprets as an authorised deactivation signal. A physical relay cannot receive a command. There is no communication channel for an attacker to exploit. The relay is open or it is closed. That is the entire threat surface.

For a detailed technical explanation of CAN bus versus relay, see: CAN bus vs relay — the difference that could cost you £800.

What building and installing every device yourself actually means

Every competitor in the market separates the manufacturer from the installer. Ghost is made by Autowatch and installed by their approved installer network. Pandora is made by Pandora and fitted by their registered engineers. The customer buys from one entity and is then connected with a separate person to do the installation.

I do both. I designed the product and I fit it at your door. This matters for reasons that are not just marketing.

What I am building towards

LockCar is at an early stage. I have sold and installed a number of devices professionally, and significantly more informally before the business was formally established. The products are working. The feedback has been good. The market gap I identified when I started building this is real and it has not closed.

What I want to build is a vehicle security company that is known not for its marketing but for its engineering. A company where the person who made the product is the person who stands behind it. A company where choosing relay over CAN bus was not a commercial calculation but an engineering principle.

There are larger companies in this market with better brand recognition, bigger installer networks, and more advertising spend. Ghost is a better-known brand than LockCar, and it will be for a while yet. But brand recognition is not the same as technical superiority, and in the long run, I believe the market rewards the product that is genuinely better for the car it is protecting.

In 2025, the top three most stolen vehicle makes in the UK according to DVLA data were Ford, BMW, and Toyota. The relay attack method that drives most of these thefts has not become harder to execute. The devices to carry it out have not become more expensive. The problem is not going away.

The nine products I have built so far

LockCar currently offers nine products across three categories. Every one of them is relay-based. Every one of them was designed and built by me. Here is the range:

The IC3ST (£139) and IS357 (£149) are the products most individual car owners should start with. Both are standalone, requiring no separate Main Control Unit. Both use wireless proximity tags for hands-free operation. The IS357 extends detection range to 5 metres and adds Bluetooth and smartwatch support. Neither touches the CAN bus.

The ONE Plus (£199) is the most feature-complete product I make. It adds 4G remote access, live camera, GPS and GLONASS tracking, automatic night immobilisation at preset hours, and Face ID driver recognition. Fleet-grade capability at a price that is accessible to individual owners, because there is no distribution chain between the manufacturer and the buyer.

The lower-end products in the range — the i124, i125, i226, ic326, and iS326 — are primarily for dealer and installer partners, or for customers who need a device to integrate with an existing LockCar MCU setup. They are available at wholesale pricing for garages and auto electricians who want a reliable relay product without the ECU comebacks they have seen from CAN bus alternatives.

One thing I want to be honest about

Building a vehicle security product from scratch and installing every unit yourself is not a scalable business model in the traditional sense. I know that. If LockCar is going to grow, the installation side of the business will eventually need to involve trained partners. That is a problem I am thinking about carefully, because the thing that makes LockCar different today is the direct line between the person who built it and the person who installs it. Any growth model that breaks that line breaks the thing that makes this worth choosing over a more established brand.

I do not have a clean answer to this yet. What I have is the commitment to not grow in a way that compromises the quality of the installation or the accountability of the person doing it. If and when LockCar trains installation partners, those partners will be trained by me, using my devices, with my technical knowledge behind them. The goal is to extend the accountability, not to replace it with a layer of professional distance.

I say this because I think you should know it. If you are making a decision about which company to trust with your vehicle’s security, you should understand the stage the company is at and what its trajectory looks like. I am not Ghost. I am not Pandora. I am an engineer who built something better than what was available, and who is now working out how to make it available to more people without making it worse.