Ive looked through some threads about some performance things on here. Im contemplating on doing some exhaust work but want to keep it a single out exhaust. I want some sound to it but not much. Would a header kit do the job without sounding bad on the stock muffler. Would the header kit make much difference on the power? and should i just do the muffler or what not... Also is their any easy performance chips you can install or are their just piggy backs. Ive seen the overkill tune mentioned a few times. I would like to keep the car for a long while and not suffer any thing from it in the future.