Technology designed to make it impossible to steal your car is backfiring as thieves equipped with high-tech gadgets are targeting vehicles with certain security devices.

Thieves equipped with relay boxes have been able to steal high-end motors without as much as touching the vehicle's key fob.

The vehicle's key fob sends out a signal which can be intercepted by criminals equipped with scanners and then relayed to an accomplice who will use the signal to unlock the car doors and start the engine.

The key fob may transmit the signal even when the vehicle is not in use, although it can be switched off to prevent theft.

On the 'nick list' Mini Clubman

Thieves also use lock jammers which prevent the car's owner locking it with its fob, reports the Chronicle Live .

This has led some drivers of prestige marques to use old fashioned, low-tech devices such as steering wheel locks as a visual deterrent to criminals.

Which cars are on the 'nick list'?

Audi : A3, A4, A6

BMW : 730d

Citroen : DS4 CrossBack

Ford : Galaxy, Eco-Sport

Honda : HR-V

Hyundai : Santa Fe CRDi

Kia : Optima

Lexus : RX 450h

Mazda : CX-5

Mini : Clubman

The Audi A6 is also a thieves' favourite

But don't panic if you own one of these. PetrolPrices.com advises: “Keep your car key away from your front door in a metal box, metal safe, metallised signal blocking pouch, microwave, or fridge.

“Fit a tracking device to your car

“Invest in a steering wheel lock, which acts as a visible deterrent.”

Putting the keys in a metal box, or in the microwave or fridge, stops the signal from the thieves’ device from getting through.