I believe the 2003 E Class (W211 chassis) is the FIRST MB to have front mounted crash detection sensors, out on the radiator support. This was found neccesary due to the efficiency of the crumple zone, the deceleration in the cabin has slowed to the point of making this relocation neccesary. Up until then, the sensor in the cabin was "fast" enough to deploy the airbags in time.
At least with the older system (sensor integrated into the module)
you don't need to worry about the wiring.