The Mercedes-Benz S400 Hybrid ESF Safety Prototype made its debut last fall, and we brought you the official details on the car then, but this week TheCarConnection's John Voelcker got to spend some time with the car in the high-tech safety-featured flesh.

One of the most unique aspects of the latest ESF Safety prototype is its heavy use of inflatables--from inflatable door bars, to size-adaptive air bags to our favorite, though it's still years away from production, the "braking bag."

Functioning much like a typical in-cabin airbag, but wrapped in steel and rubber, the braking bag senses an emergency-stop situation and deploys to increase the amount of friction the car applies to the road, and also lifts the front of the car to reduce dive and improve the angle of impact with another car.

Catch the full roundup of the car's safety features over at TheCarConnection.

[TheCarConnection, Mercedes-Benz]