'Biscuit tin' method can stop your car from being stolen
A private investigator warns that most car owners usually make one crucial mistake
Thousands of vehicles were reported stolen across the UK in 2025, with approximately ten stolen from driveways and parking areas every 10 minutes. Drivers of certain models could be at risk - and it is not always the most flashy cars that catch thieves' attention.
Vehicles are frequently stolen and dismantled for parts as thieves try to make quick cash, according to a crime specialist. But taking some DIY security measures can be as simple as using a kitchen item you'd never associate with protection.
Christopher Thomas, an investigator of UK Private Investigators, has handled numerous stolen-vehicle recovery investigations. He warns that most people commit one critical error that turns their vehicles into easy targets for theft in under 10 seconds, reports the Express.
He said: "For most of us, our cars are vital to how we live. We use them for work, to take our kids to school, to go shopping, and to get from point A to B. For criminals, our cars can be a bit of fun or a quick earner.
"I've worked with car thieves to understand their methods, so I can better advise my clients on how to keep their cars safe, and some of the methods these people use would blow your mind. I've seen cars being opened with tennis balls pressed against the lock, I've seen windows being slid down with tape, but by far the most common is by boosting the signal from your car key to your car."
Keyless vehicle theft gadgets are sold on the dark web for upwards of £15,000, but criminals with some expertise can construct their own relay-boosting equipment for merely a few hundred quid. According to the specialist, the greatest blunder motorists commit is positioning their car keys too near to the entrance.
He explained: "Your car sends out a signal every few seconds looking for your key. When your key is in range, it talks back to your car and opens it." Leaving your keys near the front door makes it straightforward for criminals to tap into your signal and steal your vehicle.
However, with certain devices, simply moving your keys elsewhere isn't sufficient. Signal-blocking pouches are readily available online, though their effectiveness varies considerably, so it's worth testing them yourself before relying on them.
A more budget-friendly yet equally effective option is a metal biscuit tin. Chris said: "We have all seen these biscuit tins in the shops or in people's homes".
"While it's a bit strange, putting your keys in one of these tins stops your car key from broadcasting the signal back to the car, even when boosted. There's a simple test you can do to see if your biscuit tin will work.
"All you need to do is get someone in your household to phone your mobile phone, then put your phone in the tin. If the line goes dead, then the tin will work for your car keys too."
Metal tins function as a Faraday cage, dampening or completely blocking the signal emitted by your key. This leaves car thieves with little or no signal to amplify, and without it, your vehicle becomes considerably more difficult to steal.
