A list of the most easy-to-hack cars has been compiled by German automotive body ADAC. 24 models appeared in the report, including Audi, BMW, Citroen and Ford.

Hacking typically involves two individuals with radios. One hacker's radio is used to harvest the signal from the vehicle owner's fob. This is sent to the radio of the other hacker, potentially hundreds of meters away, who uses the signal to gain entry to the car and turn on the engine. Attackers need to be a few metres from their targets. Since the vehicle's think the signal is genuine, alarms are not activated.

The modern car's vulnerability to hacking has been demonstrated before, but the list from ADAC (Allgemeiner Deutscher Automobil-Club e.V) represents the first time such a comprehensive run-down of at-risk cars has been published.

According to ADAC, radios used in such attacks can cost as little as £150. Thieves are subsequently difficult to locate because the systems leave no trace.

ADAC's website states: "In tests, our experts were able to open cars with [keyless fob] locking system by means of a self-built wireless extension within seconds and [get away]. This left no visible burglar or tracks."

The organisation has posted CCTV footage of what is believed to be thieves stealing a car using the above techniques. Watch the clip here: https://www.youtube.com/watch?v=xHCUpLBGIKQ

ADAC urged the industry to take action on the issue.

Top 10 "most hackable" - cars according to ADAC
  1. Audi: A3, A4, A6
  2. BMW: 730d
  3. Citroen: DS4 CrossBack
  4. Ford: Galaxy, EcoSport
  5. Honda: HR-V
  6. Hyundai: Santa Fe CRDi
  7. Kia: Optima
  8. Lexus: RX 450h
  9. Mazda: CX-5
  10. Mini: Clubman