I just got this, and obviously don't want to void my warranty, but where can I start to get better gas mileage (other than driving less aggressively, which I've already taken care of)? And, yes, I know that most people want their subies to go fast, but I don't much care about the speed or power... If I did, I would've gone with the WRX.
One friend suggested getting my cam ground for economy. Others mentioned a grill block, rear wheel skirts, front lip, side skirts, beatrush-style under panel/tray, and a perrin air filter. I have zero experience with this sort of stuff and very few tools, but I have several friends with welding shops, tools, carbon fiber set ups, etc, so I imagine I can have them help me with some of the work and can find shops to do/fabricate the rest.
So, for a completely stock 08 2.5i, what's the most bang for my buck that won't void my warranty? What works? What doesn't? (And, no, I don't much care if if makes the car look "ugly") Any advice would be much appreciated.