failsafe and fuel filter first, then think about firm rear springs or firmer oil in the rear. 6V hump pack would be good to get before you start to do a lot to it - gives the servos a power boost from the 4.8V AAs, and lasts ages between charges. Then I would suggest strengthening areas before putting performance parts on. Start with the diff (hd middle gear, hd diff shafts, ajust. diff springs), get some nice (and expensive) shiny CVDs, alum. hexes...and the carbon fibre brake disk is good, as is the hd disk hub it mounts on... this is just off the top of my head, look at the big thread for more!

If you look a few pages down the forum, theres a 10 page 'rush evo hop ups' thread, it has everything about most area's and parts to replace and just general advice. Take your time to read it ALL, and you will know a lot more about the car. Very useful.