I haven't got my owner's manual handy right here; but there is a button on the dash that one pushes for just this purpose. Let's say that it's a cold winter day. The wife, significant other, GF, or just a hooker, needs to run into the store to get something while you wait in the car. You don't feel like running the car and wasting all of our precious resources, so the SLK has this nifty button on the dash that one pushes to provide left over heat in the engine..............Not one politician REQUIRED Mercedes to do this, just your friendly engineers at Mercedes.........God bless......Dennis