Haha, wow old post!
I DID get the y-pipe shortly after, but even with an ebay exhaust (not the dual fart cannons, but the single in, dual out) AND RL Ypipe, I went up against an all stock '09 3.5 CVT coupe (like mine) and we were almost even up till 80 mph, after which it SEEMED like I pulled ahead just slowly.
Moral of the story - my car sounded awesome, but was maybe .05 seconds quicker than stock.
His turbo Altima coupe though...even with 3 adults seated that thing hauls...