Carscoop Aug. 3, 2014
Since current legislation in most countries doesn't actually allow fully autonomous cars on their roads, Mercedes-Benz was required to fit additional sensors on the steering wheel in order to detect that the driver keeps at least one hand on the wheel. If it detects that the driver isn't using the steering during a given time, the Steering Assist system is deactivated.
Closely following the KISS principle, it seems that the steering wheel sensor is actually based on weight, so the German owner of a Mercedes-Benz S 500 decided to trick the system using what appears to be a can of juice.
The weight of the soda can simulates the driver using the steering wheel, which in translation means that the car can drive all by itself on the German Autobahn.