The consumer group analysed research from the General German Automobile Club (ADAC) to evaluate the impact of keyless attacks and found that hundreds of popular cars are vulnerable to keyless theft.

They include four of the UK’s best-selling cars in the UK in 2018: the Ford Fiesta,Volkswagen Golf, Nissan Qashqai and Ford Focus.

Only the Vauxhall Corsa was deemed safe from this type of theft and this is because it does not offer keyless entry and start.

ADAC tested a total of 237 keyless cars and found that all but three of them were vulnerable to keyless theft, also known as ‘relay attacks’. Of the total, 230 could be unlocked and started using relay boxes, while a further four models could be unlocked or started.

The only three keyless cars that ADAC has tested that were not susceptible to relay attacks are from Jaguar Land Rover – the latest models of the Discovery and Range Rover, and the 2018 Jaguar i-Pace.

Which? pointed out that thieves have been using keyless theft for several years, but manufacturers continue to make new models that can be stolen in this way. This means there is an ever-larger pool of cars for thieves to target.

What’s more, many people spend money installing keyless technology. Although this offers convenience in everyday life, it means that individuals are effectively paying hundreds of pounds to make their car less secure.

For example, Which? found the cost of equipping the 2018 model of the VW Toureg with keyless entry costs £700, and it comes to £500 for the Volvo V60 (2018).

Harry Rose, Editor of Which? Magazine, said: “The fact that so many cars on the road are susceptible to keyless theft simply isn’t good enough. We want manufacturers to up their game when it comes to making their vehicles safe from theft.”

Five tips to protect your car from theft

Here are five ways to minimise the threat of car theft, according to Which?.

• Use a steering wheel lock. The best locks are approved by Secured by Design and cost around £120.
• If you use the remote-locking button on your key fob, make sure you check the doors are actually locked – this will ensure you beat any thieves using a remote signal blocker.
• Keep your car keys out of sight at home and never within close proximity of your front door. If you own a keyless car, contact your manufacturer to find out how you can protect yourself.
• Don’t make your car look more appealing to thieves than it already does. For example, never leave valuables on view.
• Cars are far more likely to be stolen at night. If you can’t park overnight in a locked garage, try and park in a well-lit area, or consider investing in CCTV.