The Needswings CAI is time consuming for a first timer. Moving the power steering tube is a piece of cake, replacing it, if and when you add a supercooler, for me was difficult. Peak dyno numbers were too close to make a definite statement about how many HP. The dual seems to give a bit more grunt down low. The single is all you really need, but we all want the dual, be it for the balanced look or a little extra performance. I started with the single and currently have the dual. No other upgrades are needed. I had a pulley, CAI for over a year before getting a tune and still don't have any fuel upgrades.

Les

I should add that no body can walk by the car with the hood up and grill off and not stop and stare. The visual impact of the dual is off the charts.