Originally Posted by SpeedElement

Well if it makes you feel better, we ordered coilovers before taking delivery of our shop Nismo, and long tube headers and AEM intakes were installed before we hit 500 miles

Which part are you nervous about? The bottle replacement or the bumper removal? All of the CAI units on the market will require some type of modification-

AEM- bottle relocation/replacement, metal ducting modification (Nismo model specific for guide modification). Bumper removal during install.
Injen- bottle replacement. Bumper removal during install
Stillen- Metal air guide modification (Nismo model). Bumper removal during install.

So unless you're willing to just invest in K&N/Mines/HKS drop in filter elements or even a short ram intake (which don't produce significant power gains compared to CAI), you're looking at some type of modification.