Looks like Mercedes has developed a new type of air bag that deploys underneath the car. Reportedly this helps to stabilize the car in the case of an accident and provide further protection for the driver and passengers.
-providing friction to slow the vehicle even further;
-stabilizing the vehicle by providing more contact with the road;
-minimizing the car's "dive" as it brakes, which, in Daimler's words, "improves geometrical compatibility with the other party in an accident." (In other words, you'll take a hit on par with the other vehicle, and you won't wedge under, both of which can minimize injury to you and your car.)