Oh, to address your first question...for cheaper mods, I would do maintenance first...i.e. clean throttle body, add oil supplements and fuel injector cleaners, change oil and tranny fluids (syn), check tire pressure, reduce weight, tune up engine (change plugs, wires if necessary).
Other than that, cheapest mod is probably adding an intake, best bet is going custom CAI. After that, there's changing the y-pipe, high flow cat and catback exhaust system...all cost a bit more money. Then after that, who knows? Port and polish...custom headers? Electric fan? Our rad fan is run hydralically...and electric fan should help a bit. I would think anything after that would get pretty pricey....the 3VZ has absolutely no aftermarket products...:cry:

: ..that's why I concentrate on looks instead.