For the NA and getting the most HP/$ the NW dual is a bit overkill. The increased flow from the second tube does not justify the cost IMO as the NA isn't as hungry for air as the supercharger. A single NW flows the best out of the other available options if you want the most performance . Good compromise would be other Mercedes OEM stuff (c320 intake) Hotter and not as much power as the NW but improvement over stock. Short list of reasonable priced mods for the NA would be Tune, Throttle Body, intake, injectors. After that you start spending more $ per HP. As to where to start it doesn't really matter that much. If you go tune first you will want to get it redone after adding additional components to maximize your gains.