Originally Posted by King

I really don't know if an aftermarket CAI is really going to make any difference at all. During my delivery process, the BMW rep was there and he went over the design of the engine and pointed out how the air intakes have been pointed right to the kidney grills. I guess in the E53, the intake was pointed somewhere lower behind the front bumper. He also pointed out how the kidney grills were re-designed and the angle of the grills forces more air into the engine. I would say save your money or spend it on something else!