The STI rear bar will fit if you run the mounts on the outside. The key is endlinks. The factory Endlinks will rub. The Front sway will not fit from sedan to wagon.
The STI Rear is a little wider than the WRX/RS rear bar for some reason.
Aftermarket bars, I'll agree. Stock STI bars have a bend on the right the aftermarket ones don't. That bend won't allow the bar to slide to the left enough to put both endlinks on the inside.
speaking of sway bars, i dont' think that white line i have is for my car. im sure it fit and all that. but looking it up i think it's for like a 02+ wrx where it doesn't have to clean hedders just a down pipe or something.
I'm telling ya man, look at the pic above of the STi vs stock bar, RH pic. Look at the bend in the STI bar right where the mount is located on the stock bar. It keep the STI bar from being able to center on the car. Look at the whiteline pic. It doesn't have that bend, therefore you can center the bar on the car. When you have both sitting in front of you its easy to see.
speaking of sway bars, i dont' think that white line i have is for my car. im sure it fit and all that. but looking it up i think it's for like a 02+ wrx where it doesn't have to clean hedders just a down pipe or something.