Here's a novel idea - Maintenance. Period.
Why the hell would you mod a car that is 5-10 years old when you can achieve significant gains just by returning it to "as-new" running condition?
I'm thinking all synthetic fluids (oil, transaxle, brake, etc) an alignment, wheels balanced, (maybe new tires), bushings, radiator flush, injector flush, TB and intake cleaning, etc.
I like Kcar's idea too.
