Excellent input, guys.
With motors and pipes now being designed and engineered around INS boxes, it's amazing there is still so much resistance to them. Everything I have heard says the performance losses are minor, offset by the increase in mileage and decrease in sound. For me, there's no reason not to use one.
Various bodies and different manufacturers make the rear spoiler or wickerbill for most bodies. What does running one do, and what can be expected to change when moving it up and down?
Also, does everyone generally run 35s (tires) on the front and rear, and on a track with very low wear, would using a softer tire be advantageous?