Get a chance to buy a stock 07 STi catback only 500km on it. Will it fits my 02 WRX? Any performance difference? or better off an aftermarket catback system? Any advise? I don't like too loud. What about the sound?
It will be slightly deeper than stock with no fitment issues. But no power gains. If you want something slightly louder but not annoying there are many other and better choices. Cobb, Perrin, Prodrive, SPT, Borla, GP Moto, just to name a few.