i have an injen CAI intake and sti axleback exhaust on my 2.5i. i'm really happy with the sound and engine response from those mods. don't really care for speed atm. it's a slow car to begin with
handling is where it's at! i got the CAI and axleback for the sound really. call me rice or what not, but i like the rumble of an exhaust and sucking of an intake when i drive
makes knowing shift points easier too (without looking at the tach).