Contour Enthusiasts Group Archives Forums Modifications Zetec Performance What should be the first mod?

I'm a college student, and don't have much extra money, maybe $500 to spend on the car for an entire summer's work. The mods I've done so far, and like:

Ford racing 9mm spark plug wires ($40)
new rims/tires 15" ($600)
SVT sway bar w/ poly bushings ($30)
Silverstar bulbs ($30)
Elky mesh in grille/bumper ($45)
some fogs ($20 for proburners, $50 for hellas)

I've done many other things like audio, etc., but there is plenty of things to do for cheap.