Police have released video footage of tech-savvy car relay thieves taking around 40 seconds to steal a Mercedes from a driveway.
The car stolen by two crooks in the Marston Green area of Solihull has yet to be recovered following the theft in the early hours of February 21.
The video shows two men approaching the victim's house, carrying relay equipment capable of receiving signals through walls, doors and windows, but not metal.
In the footage, one of the men can be seen holding a relay box in front of the property to transmit a signal from the vehicle's key to a second device being operated beside the driver's door.
West Midlands Police said the car's systems were tricked into believing the key was present, unlocking the doors.
The offence occurred at around 5.30am at an address on Maple Leaf Drive.
Mark Silvester, from the West Midlands Police 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."
The area's Police and Crime Commissioner, David Jamieson, recently voiced fears that such thefts could herald the return of the crook lock, and has asked for manufacturers to increase security.
Anyone with information about the theft is urged to call West Midlands Police on 101.