Exhaust is the first thing that comes to mind. After that is replacing the stock shifter with an MGW shifter. Suspension mods and tires would be next on my list and then a tune (if you aren't worried about the engine warranty). Although I'm sure many people would reverse those last two.
2012 Kona Blue GT Premium 401A, Manual, 3.55, Steeda Pro-Action Shocks, Struts, Sport Springs, LCAs, Adjustable Swaybars, Adjustable Panhard Bar, BMR Relocation Brackets and Adjustable UCA, Driveshaft Shop Aluminum Drive Shaft, Airaid CAI, MGW Shifter, GT500 Axle-Backs, 3M Clear Bra and Tint, Side Window Louvers, JLT Oil Separator, Staggered MMD Zeven Wheels and Mickey Thompson Street Comp Tires, Bama 93 Race Tune