Hmm IDK why but I dont care for the 5. IMO alot of $$$ for not that much power gain. Just looks cool. I'd go with the 4 turbo back Stainless steel for sure. You should be able to change the stock peace with the cat back pretty easy. All you'll need is a 4-.3.5 adapter. Your making a good choice with MBRP. Im impressed with everything on mine.
