I just got my 2005 Mazda6s Hatch a week ago... I'm looking at getting some rims, so I can't afford too much more. What is the best engine upgrade I can do for the money? Would like to stay under $300... Cold air intake? If so, what brand? What about a chip, if so, what one? If either of those...then what? And what does it do for me? Also, I've gotten up to 115, what is the govenor at? Thanks!