[a8 tech]

If the engine was running and the key was taken away from the vehicle or stolen then the vehicle will still run until the engine is turned off then it wouldnt restart
,but the kessy would recognise the key was no longer in the vehicle by a symbol on the dash.If the engine wasnt running and the spare key was in the area of the vehicle (boot) then there is a possibility that the car would (tryed this today and no start key not identified in the boot)start however it wouldnt lock from the kessy when the driver gets out as the kessy will see a key in the area(i think).If there are no keys within 3 meters then it wouldnt start as the start authorisation would stay in the security setting until a key signal was generated which isnt hackable as the sequence of events to actully start a vehicle va keyless entry is complex.If you require a full explnation please ask and i will read my info.