Like you say Corey_R, you cannot have the zero fuel flow without a gear engaged or the engine will stall. Dunno about the 6 but with the DSG7 if you were to drive along at say 100kph in 7th and take foot off accelerator pedal & lightly brake, it will work its way down thru all the gears keeping revs just above idle, while to the driver you are just mindlessly coasting to a stop. All the while fuel flow will be zero. Eventually when speed drops to a point where there is insufficient energy to windmill the engine just above idle, it will re introduce fuel and presumably ign. Very clever I reckon.