Eughhhh XI..... honestly unless you are rookie who can't properly feather the throttle or too cheap to buy proper snows I think it's an unnecessary option. The extra dead weight & rotating mass, plus loss of steering feel isn't worth having some extra traction during winter. Plus your car rides higher and looks worse. These cars have 50/50 weight distribution and with a proper set of winter tires (not that low-sidewall performance snow tire BS) the car is a beast in the winter. Plus power over-steer in low traction situations are too much fun in a Rwd car.
In terms of performance mods you are kinda limited to an ECU tune or cat deletes. Exhausts are just for the sound. If you want real gains outta your exhaust you have to start hacking out cats. Our primary cat is in the header so if you wanna remove that you are best off buying supersprint or MMW catless headers but they are expensive and run into all sorts of emissions issues.