I would say, if you plan to go beyond basic bolt-ons ( bigger turbo, etc), then go with a different exhaust with 2.5 in diameter piping or larger. If you plan on just basic bolt-ons with the stock turbo, then the Ford Racing, Borla or Magnaflow will work great. There is no magical horsepower to be gained from just a cat-back...maybe a few hp at best. It's a mod that compliments other mods....only when those other mods really need the extra flow.