Rules are different for track and a daily driver.I will have to agree with Jason, you have to test to see what is best for your car and driving conditions. Also look to see what the high end really fast cars run or don't, cost not being a factor.
People often ask why their car seems faster when it's cold out. We know why.
I tested an open cone (again) last summer versus my cai and around town at 45 mph or so. The car was noticably slower with the open cone and intake temps never dropped down to the 1 -2 * above ambient that was afforded by the cai. I really wanted the open cone to be better because removing it would clean up the engine bay.
Anyone know what the fastest V6's at Branson had as far as mods go?