Mercedes - Benz claims efforts have been made to make the cabin quieter than before, with additional insulation of the suspension from the vehicle body,
aeroacoustic measures, and increased structural rigidity leading to a significant reduction in interior noise levels.
The B9's drag coefficient value of 0.23 is class leading, and is derived from a range of subtle
measures, including the outer lines of the air inlets that integrate additional openings (they guide some of the airstream over the wheel well), wing mirrors positioned on the door sills (narrow stripes enhance
aeroacoustics, amber light below it is a unique blind spot assist method), narrow trim on the rear windows and a largely smooth underbody.