Originally Posted by TMP
This is a great question, as i have been wondering this too....
I think you can drive the car off, and only when you stop engine (eg by pushing the button) you would be unable to the re-start .
(This is how our E60 works, as you can take the car out once the car have been runnnig for 30 seconds and then restart car without the key)
So I tested this out a little further, started the car as normal, went into the house and left the key inside.
Drove off and no warning noises - not sure I like this "feature"!