Footage has emerged of two tech-savvy thieves stealing a Mercedes from a driveway in less than 40 seconds.
The men used relay equipment which is capable of receiving signals through walls, doors and windows.
This transmitted a signal from the vehicle's key to another device being held near the car – and tricked the car's systems into believing the key was present, unlocking the doors.
West Midlands Police say the theft happened at about 5.30am in the Marston Green area of Solihull, and the Mercedes has not been seen since.
Last year, another Mercedes was also stolen in Solihull using the same technique – and West Midlands Police told Sky News that two men have been charged with a similar attempt to steal a Ford Fiesta.
Mark Silvester of the West Midland Police's crime reduction team, said: "To protect against this type of theft, owners can use an additional tested and Thatcham-approved steering lock to cover the entire steering wheel.
"We also recommend Thatcham-approved tracking solutions fitted to the vehicle.
"It is always worth speaking to your main dealer, to ensure that your car has had all the latest software updates and talk through security concerns with them."
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The area's police and crime commissioner is urging manufacturers to increase security, amid fears that such thefts could herald the return of the crook lock.
:: Anyone with information about the theft is urged to call West Midlands Police on 101.