Hey guys pretty new to the IS game. I own an Auto 03 IS300 & im wondering how far i could get in making the car faster before doing a whole engine/manual swap. I know the goto mods which are headers, exhaust, CAI, but is there anything else for an auto? Alot of the threads or things i find online are for manuals. Like for tuning aswell i dont see anything at all for an auto. Just wanted to ask incase someone out there had any info. Thanks in advance!