while people on this board prove every day that small inexpensive changes can have a big impact on FE, carmakers are slow to catch on.
still BMW these days has a number of interesting features in production that hopefully will soon be adopted by other car makers, but if nothing else, could sever as an argument next time someone redicules your cardboard grillblock etc.
theres some simplistic but cool animations that explain every feature
BMW EfficientDynamics : Air vent control