02 lancer OZ rally edition, possible upgrades?
 

Acquired an 02 Lancer OZ rally edition recently on the cheap. Only problem is that it's an automatic transmission, but I can live with that.

What's available in terms of upgrade parts? Ideally, I'd like to upgrade the intake and any components I can for the most bang for the buck. My goal is to give the engine a nice purr to it, increase mpg and general performance. Ideally, I'd like to avoid any external modification such as body kits.

Advice? links?

thanks