The debate never ends. It adds weight to the rear wheels in crappy weather. Take it from me, even in a AWD car. The ass end can come around in adverse conditions. It's still R&D'd and used in the rally events. Granted the rally cars had the wing stiffys/dividers in it to keep it still. So, it serves a purpose. If you look at it carefully enough. It's basically a spoiler/wing combo. Spoilers help you in straight line speed and wings help with turning IMHO. So, your opinions may vary. But, It's still a product pushed on the top line model. The STI limited is marketed towards luxury and Subaru put the rear spoiler lip on it. I am in no way saying the STI wing is a necessity though. To each his own...but, I'm not a fan of people trying to make their car look like a STI either. I mean that as nicely as possible. One wing isn't quite what I'm talking about. Its the guys that go all out on trying to cop the look.
That being said. Rims and good tires are a better mod. Especially if you're running the crappy RE92s. Get rid of those things ASAP. A form of EM is also a great thing to have. Back OT, sorry for the distraction there.
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae