Id like to know what is the best exhuast for performance increse on the G sedan, and how a link or some info on it...HP/Torque gains, price, etc. Thanks!!

No one has what you want on the stillen muffler or the Greddy cat-back, not that I've ever seen. Pretty much butt dyno's only.

Stillen will be introducing their true dual system for the sedan in the short term (within 60 day's would be a safe bet).

Ivry 6mt sed
Crawford Pleneum
Injen CAI
22" resonator
Cusco sway bars
350Z springs&struts
Enkei RPM2