Dinan's high flow intake system for the 550i dramatically increases intake air-flow volume and velocity as well as ensuring the lowest possible intake air temperatures for maximum power gains, as well as improved throttle response. The system takes full advantage of the ram-air effect by adding a second air inlet in conjunction with the stock configuration, force-feeding more cool, oxygen-rich air to the enhanced air box. The system includes a complete replacement air box and lid, designed to increase overall volume and accommodate the additional air inlet. A special high flow filter element is included, reducing the restriction presented by the stock filter. The airbox and lid are molded from a composite material that has been chosen specifically for its ability to resist power robbing under-hood heat and the design provides for a completely sealed air box, maximizing pressurization for optimum performance. Air from the secondary inlet passes through custom-molded ducting, including a visible section manufactured from carbon fiber, also designed to reject underhood heat and provide maximum flow. The high flow intake system alone produces a substantial 18 horsepower gain. The intake note takes on a subtly more aggressive tone at wide-open throttle that will be music to the driving enthusiasts' ears.