Police have seized car theft "relay" devices in what they believe is a first for a UK force.
It comes after CCTV footage issued last month showed thieves in Solihull using a device - that tricks a car into thinking the key is present - to steal a Mercedes in less than a minute.
In the CCTV footage of the Solihull theft, one of the men can be seen waving a box in front of the victim's house.
The device receives a signal from the key inside and transmits it to the second box next to the car.
The car's systems are then tricked into thinking the key is present and it unlocks, before the ignition can be started.
http://www.bbc.co.uk/news/uk-england-birmingham-42370086