Originally Posted by AntiVenom

if what you want is a great sports touring car (assuming you mean something that drives great but is comfortable to ride in on a daily basis or over long distances) you already own that. if you are looking to do some time attack. add a bigger oil cooler, grippier tires, better brake pads, thicker sway bars, and get on a track. you don't need a body kit to achieve either one.

now if you are going for a certain look and want to also be able to tell folks that it isn't just for looks, then the Nismo and Amuse kits claim improved downforce, and have been tested. Although, there is a thread floating around that at least from a theoretical standpoint claims that the Nismo kit doesn't much if any improvement at speeds. Note the use of the word claim in the last couple of sentences, very little substance there imho. If anything I'd be inclined to believe the fact that they in fact do jack diddly.