It seems like the bumper serves to minimize the airflow volume through the cooling system,harvest the remaining cooling air from a lowered frontal stagnation location,while limiting stagnation pressure from the base underside of the original M-B nose,thereby restricting underbody flow.All good!
The airflow would be deforming well in advance of the car even without the new nose,as Ludwig Prandtl reported on in the 1920s,with his 'lines of discontinuity.'
Here you can see it with the Schl'o'rwagen
The quasi-NACA inlet at the driver's side upper grille location brings in the rest of the needed air.
It's a stylish way to kill a couple birds with the same stone.
