The Mercedes 'Concept IAA' switches automatically from design mode to aerodynamic mode, whereupon numerous active aerodynamic measures alter its appearance. As a result of this transformation, the Cd value improves from 0.25 to 0.19 - a new world record for a four-door four-seater. The frontal area totals 2.16 m2.

The front flaps in the front bumper in front of the wheel arches move outwards by 25 millimetres and 20 millimetres to the rear, up to the rear edge of the wheel crescent. This substantially improves the inflow of air to the wheels and the flow of air over the front wheel arches.

The louvre in the front bumper moves 60 millimetres to the rear, improving the flow of air towards the underbody.

The Active Rims alter their cupping with the aid of centrifugal force from 55 to 0 millimetres, transforming them from sporty 5-spoke wheels into flat disc wheels offering exemplary aerodynamic characteristics.

In conjunction with the diffuser, the rear extension which is extendable by up to 390 millimetres ensures that the air flow hugs the vehicle more closely and that the after-flow zone behind the vehicle's rear end is substantially smaller. This results in a considerable reduction in drag. The rear extension in 'boat tail' design consists of eight segments produced in CFRP in a sandwich structure which close to form a ring..