I would start with cold air intake, exhaust, and then headers. I also just purchased an 09 approx. 2 weeks ago and love it. Personally, I'm going with tint, hid's (fog and regular) and then begin to work on engine performance. I don't see a lot out for the 09 but from what I've read some of the 08 mod's will still fit. Be sure to research any item before buying to make sure though!