I have wanted a Subaru for a looooong time and finally got one. My wife and I commute a good hour to work over a mountain road and decided on the 2007 Impreza 2.5i SE as a commuter car. We have owned the car for about 1 1/2 years and just paid it off. So now we are looking in to slightly modifying it. The first and only thing we have done was replaces the stock air filter with a K&N filter (big whoop I know).

I don't want to do that much to the car - exhuast, air intake, brakes/rotors and supsension kit is what I am looking to do. Are the WRX parts exhaust/intake interchanagable? Any brands that are worth $$$ or any that I should avoid? Also cold air intake vs. ram air?