LockCar IC3ST review, the UK’s best standalone dual-factor immobiliser

The LockCar IC3ST is the company’s most popular standalone immobiliser. It combines an encrypted 2.4GHz proximity tag with mobile app authentication, creating a two-factor lock on the start circuit with no separate MCU required. This review covers its technical specification, how it compares to similar products, and who it is best suited for.

LockCar IC3ST technical specification

The IC3ST is a standalone immobiliser device that requires no separate MCU or control unit. It integrates directly into the vehicle’s start circuit, introducing a 20A relay break that prevents engine start unless the device receives an authenticated signal from either the proximity tag or the mobile app. The proximity tag communicates via a 2.4GHz encrypted channel, distinct from the vehicle’s passive keyless entry frequency, meaning relay equipment that can amplify the key fob signal cannot also replicate the IC3ST tag signal.

The 20A relay rating covers the full range of passenger car and light commercial vehicle starter circuit current draws. Supports both 12V and 24V installations, making it compatible with cars, vans, pickups, and motorhomes. The authentication event in hands-free mode is automatic: as the owner approaches the vehicle with the tag in their pocket, the IC3ST detects the tag signal and disarms. Walking away re-arms the device. The mobile app provides backup authentication for situations where the tag is not available and allows status monitoring and configuration.

Installation dimensions are compact enough for concealed mounting in standard dashboard voids, under-seat locations, or behind panel trim. The device has no external indicator lights or sounds in normal operation, making it invisible to a criminal scanning the vehicle’s interior for aftermarket security hardware.

IC3ST compared to CAN bus immobilisers and GPS trackers

The IC3ST differs from CAN bus immobilisers in a fundamental way: it is not a CAN bus device. It connects to the physical start circuit with a 20A relay, making it immune to CAN bus injection attacks that can in some circumstances override CAN bus-based immobilisers. The relay break is hardware, not software. It cannot be overridden by any electronic command sent over the vehicle’s CAN network.

Compared to GPS trackers, the IC3ST provides prevention rather than recovery. A GPS tracker locates a stolen vehicle after theft. The IC3ST prevents the vehicle from being started in the first place. For owners who want both prevention and recovery capability, the LockCar One Plus combines a relay immobiliser equivalent to the IC3ST function with 4G GPS tracking and live camera in a single integrated unit.

The IC3ST is most suitable for personal vehicle owners and single-vehicle businesses who want a standalone immobiliser without the ongoing connectivity costs of a 4G-connected system. It provides the core relay break function at a competitive price point with no subscription requirement.

How LockCar stops this threat

LockCar installs a hardwired relay break in the vehicle start circuit. This break is positioned downstream of the factory immobiliser, the OBD port, and the CAN bus. Even if a criminal performs a successful relay attack or CAN bus injection and satisfies the factory security, the engine will not start because the LockCar relay is open. Closing that relay requires a second, independent encrypted authentication that relay equipment cannot replicate. LockCar is designed and manufactured in the United Kingdom and installed by mobile engineers at your home, workplace, or any accessible location.

LockCar recommended products

Top recommendation

LockCar IC3ST, £139

Primary recommendation for this vehicle type

UK-manufactured and professionally fitted. See full product page for specifications and pricing. Mobile installation UK-wide from £150 fully fitted.

LockCar IS357, £149

Immobiliser, tag, app, compact form

The IC3ST’s sibling model with a slightly different form factor and feature profile. Also standalone, also dual-factor, with wireless tag ID and mobile app. 12/24V. Suitable for all vehicle types.

LockCar One Plus, £259

4G GPS, camera, immobiliser, combined

For owners who want the IC3ST’s relay break function plus 4G GPS tracking and live camera. The complete solution combining prevention and recovery in one professionally installed system.