Mike, your point is valid. However, a true CAI consists of a conic filter located in the front of the car, ceramic coated intake tube to insulate the tube from the engine heat. The usual OEM setup consists of resonator, filter, and filter box. This setup impedes the air flow(breathing), therefore, it is not an optimized setup but less costly in designing and mfg. and less noise
Noise is a big NO NO to many MB traditional buyers!