so im not big car guy. i dont know awhole lot about them. but what i would like to know is if i was to purchase a 04/05 WRX would an exhaust make a difference in HP? and i am also prolly getting an automatic. i have no thoughts of racing this. i just simply want a nice car with good amount of speed and handling. but im just curious to what kinda of upgrades i can do to an automatic? does it make a big difference on things like what exhaust i can get? and any other mods i possibly wanna upgrade.