A technique that allows thieves to silently unlock and drive away cars is getting cheaper and easier than ever.

Car theft has evolved far beyond the traditional smash-and-grab. Today, a growing number of thieves use a method that lets them unlock and start vehicles without any physical damage or forced entry. This technique is becoming more affordable and accessible, posing a serious threat to car owners everywhere.

Understanding how this method works and what you can do to protect your vehicle is essential. This post explains the technique, why it’s spreading, and practical steps to keep your car safe.

A close-up of a car key fob next to a signal interception device

How thieves silently unlock and drive away cars

The technique relies on intercepting or amplifying the signal between a car’s key fob and the vehicle. Most modern cars use keyless entry systems that communicate wirelessly with the key fob. When you press the unlock button or approach the car, the car detects the fob’s signal and unlocks the doors.

Thieves use devices called relay boxes or signal amplifiers to capture and extend this signal. Here’s how it works:

• One thief stands near the car with a relay device.

• Another thief stands close to the owner carrying the key fob, often inside a house or building.

• The device near the owner picks up the fob’s signal and transmits it to the relay device near the car.

• The car thinks the key fob is nearby and unlocks.

• The thief can then start the engine and drive away without any physical key.

  
  

This method bypasses alarms and immobilizers because the car believes the authorized key is present. It leaves no visible signs of forced entry, making it harder for owners and police to detect theft quickly.

Why this technique is becoming cheaper and easier

Several factors contribute to the rise of this silent car theft method:

• Lower cost of relay devices: These gadgets used to be expensive and hard to find. Now, they are sold online for a few hundred dollars or less.

• Simple operation: The devices require minimal technical knowledge to use. Thieves can learn how to operate them through online tutorials and forums.

• Increased number of keyless cars: More vehicles come with keyless entry and push-to-start systems, expanding the pool of vulnerable targets.

• Lack of awareness: Many car owners do not realize their vehicles can be stolen this way or how to protect against it.

  
  

The combination of affordable tools and widespread vulnerable cars means this crime is growing in many cities worldwide.

Real-world examples of silent car theft

Cities across the globe report rising cases of this theft method. For example:

• In London, police noted a 50% increase in keyless car thefts over two years, with many victims unaware their cars were stolen without damage.

• In the United States, some states have seen spikes in relay thefts targeting luxury SUVs and sedans with keyless systems.

• Insurance companies report higher claims related to keyless theft, leading to increased premiums for affected models.

  
  

These examples show the technique is not limited to one region or car brand. It affects a broad range of vehicles and owners.

Parked car with keyless entry system in a driveway

How to protect your car from silent theft

While this threat is real, there are effective ways to reduce your risk:

• Use a Faraday pouch or box: These are special cases that block wireless signals. Store your key fob inside when not in use, especially at home.

• Turn off key fob signals: Some manufacturers provide options to disable the key fob’s wireless signal when not needed. Check your car’s manual.

• Park in secure or well-lit areas: Thieves prefer secluded spots. Parking in a garage or busy area reduces risk.

• Add steering wheel locks or immobilizers: Physical barriers can deter thieves even if they unlock the car.

• Install additional security systems: Aftermarket alarms or GPS trackers can alert you and help recover your vehicle.

• Be aware of suspicious activity: If you notice people loitering near your car or home, report it to authorities.

  
  

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Taking these steps can significantly lower your chances of falling victim to silent car theft.

What car manufacturers are doing

Car makers are aware of this growing problem and are working on solutions:

• Some brands now include motion sensors in key fobs that deactivate signals when the fob is stationary for a period.

• Others improve encryption and rolling codes to make signal interception harder.

• Newer models may require additional authentication steps before starting the engine.

  
  

Still, many cars on the road remain vulnerable, so owners must stay vigilant.

Silent car theft using signal relay devices is a growing threat that exploits modern convenience. The good news is that simple, practical measures can protect your vehicle. Using signal-blocking pouches, parking smartly, and adding physical security can keep your car safe from thieves who want to unlock and drive away silently.