A new surveillance video from Birmingham, England shows two hackers exploiting keyless technology to steal a sleeping man’s Mercedes—in less time than it takes to order something off Seamless. Released by the West Midlands Police Department on Monday, authorities believe it to be the first footage of thieves attacking a car using relay boxes, devices that can be programmed to send signals through walls.

Called a “relay crime” by police, the heist is incredibly simple. Each hacker had one box. The first box, placed on the house’s exterior, picked up the signal from the owner’s key fob, sending it to the second box, placed right next to the Mercedes.

Having received this signal, the smart lock “thought” the key fob itself was present, unlocking the door and giving the hackers full access. And because smart keys often come coupled with keyless ignitions, the theft went out without a hitch.

The entire theft, which occurred in September, took under a minute.

Police haven’t caught the thieves, but say drivers interested in keyless tech can safeguard their smart cars by equipping them with tracking devices or steering wheel locks. Or, as a last resort alternative, you could always just use keys.

[YouTube via Derby Telegraph]