There are some uncertainties when it comes to the V exhaust. I am hesitant to go with a 3 inch exhaust system especially with Corsa sticking to the 2.5 because of diff heating. I don't think we are going to see much improvement with a catback system over stock. Even if there is I am confident that an x-pipe along with some new mufflers will accomlish the same goal with a lot less money. I would have to say that headers will probably create the best bang for the buck over a catback system. What do you guys think?