bmw already offers "EfficientDynamics" models over here.
last weekend i saw a 1 series hatchback up close (my brother in law swapped his mpv company car with a coworker who went on holliday with it)
the underside is completely smoothly panneled as far a i could see from the front, and both grills have active grillblocks that close the grill off from behind these features are standard across the bmw line... i think some models also come with start-stop tech, wich basically shuts down the engine when you shift to neutral and let of the clutch, and restarts when you depres the clutch again
BMW EfficientDynamics : Air vent control