In the standard design mode, the four-door luxury coupe looks like a CLS from the near future with styling that's mixed with a little of the F 015 concept. However at the press of a button or upon hitting about 50 miles per hour, the IAA transforms into aero mode to have an insanely low drag coefficent of just 0.19. To achieve the ultra-efficient shape, the rear of the concept stretches over 15 inches to guide air down the tail. Flaps in the bumpers also extend outward, and the wheels adjust to improve the flow around the sides. To trim things out underneath, a portion inside the front bumper moves, as well.
Inside, passengers sit in organically shaped leather seats, but occupants have to look at a vast array of purple and blue LED accent lights. The big panoramic roof is a nice touch, though. It would be interesting to watch water tumble over this slippery shape when driving in the rain.
To maximize efficiency, Mercedes powers the IAA with a plug-in hybrid that's hooked up to a gasoline engine. The result is 275 horsepower and an electronically limited top speed of 155 miles per hour. On the European testing cycle, the company figures the concept could cover 41 miles solely on electric power in aero mode. Showing the gains of the swoopy transformation, that figure falls to 38.5 miles in design mode.