(CNN)More than 200 car models that offer keyless entry are susceptible to theft, a report from British consumer group Which? has revealed. The models at risk include four of the five bestselling cars in the UK, produced by Ford, Volkswagen and Nissan.
Hundreds of keyless cars are vulnerable to high-tech theft, new report says
The vehicles can be stolen using "cheap electronic equipment" purchased online, Which? said. Of the top five most popular cars in the UK -- the Ford Fiesta and Focus, the Volkswagen Golf, the Nissan Qashqai and the Vauxhall Corsa -- only the Corsa cannot be stolen using this technology, because it does not offer a model with keyless entry.
While these systems require a fob to be within a certain proximity of the car to unlock and start it, thieves can use relay boxes to boost the fob's signal. This tricks the system into believing the fob is near the car, Which? explained -- even if it's actually inside the owner's house.
Testing carried out by the German General Automobile Club demonstrated that of 237 keyless car models, 230 could be both unlocked and started using relay technology, while four models could be either unlocked or started.
Further makers with vulnerable models included Honda, Audi, Hyundai, BMW, Kia, Skoda, Volvo, Peugeot and Renault.
Three models were impervious to the relay technology, all from Jaguar Land Rover: the most recent versions of the Discovery, the Range Rover, and the i-Pace.
The affected manufacturers, Which? said, have "sacrificed the security of scores of modern cars for the sake of convenience." All of the manufacturers excluding Honda told Which? that they prioritize their cars' security against theft, and are looking for ways to improve it.
Society of Motor Manufacturers and Traders (SMMT) Chief Executive Mike Hawes said in a statement that the car industry "takes vehicle crime extremely seriously and any claims otherwise are categorically untrue."
A Ford spokesperson told CNN, "To do well here, manufacturers should basically not offer keyless technology which is counter to customer demand and feedback."
Instead of targeting the manufacturers, authorities should address the "tiny minority" who use electronic equipment to steal keyless cars, the spokesperson said, adding, "Ford and SMMT say availability of relay equipment should be outlawed, and anyone found with it who is not a bona fide industry representative dealt with as if going equipped to steal."
Ford added in a statement that owners of keyless cars should take extra security precautions, including storing their fobs in a "metal box or shielded pouch" away from their front door.
Nissan said in a statement: "We are aware of this type of attack and are fully committed and constantly working to protect our customers to tackle the ever-changing security requirements."
A Honda spokesperson said the company "takes car security very seriously" and is "constantly looking at ways to make our cars more secure."
A Hyundai representative said that "safeguarding the security and safety of our customers is crucial to us," adding that we "shall continue to develop and update effective counter-measures against all hacking and relay attacks."
A spokesperson for Volvo called this type of theft "extremely rare," adding: "We will continue working to improve and enhance our vehicles in line with the latest technological developments."
According to Which?, some Mazda, Mercedes and Peugeot cars can have their keyless entry system switched off, while new BMW and Mercedes models have added motion sensors to their fobs to ensure a car cannot be unlocked if its fob is still.
CNN has contacted all the manufacturers above for comment.