if i had a list this is what it would be, 1) TRD CAI - ~$450 - the CAI is good for bout 5kw atw 2) Cat Back Exhaust system - ~$1100 (somthing like the CES system, it was good for bout 9kw atw) 3) Low King Springs (35mm drop) + Koni Adjustable Sports Shockies (a must IMO if you are going to lower the car) - ~$1400 for the springs and shocks fitted 4) Camber bolt kit ( this is to adjust the camber on the front wheels only, gives you alot better turnin on corners) - ~$70-100 5) Whiteline Front Strut Tower Brace (im proves handling) - ~$180 all up you are looking at about $3380. after this i would also look at getting a better clutch, lighter flywheel, but these will blow your budget most due to the labour fitting costs.