I read the post to mean, what are the 'best mods for a N/A S2000.' It is also a repost of http://www.s2000.com/forum/viewtopic.php?t=629
Well, IMO, the best
mods for a NA S2000 is to go away
from NA and move to FI. Best bang for the buck. If the post said 'best mods for a SC S2000' I'd say smaller pulley, bigger injectors, Emanage.
Waste of money? It depends on your goals, I guess. There is fun in modding a car to make it unique, make it sound or look a different than everyone else's. To some, that is money well spent, even if it isn't backed up by performance figures. If your goals are to pull 10 car lengths on stock S2000's, then it probably is a waste of money.