Blackened headlights will look good. Carbon front lip would be win.
Its fine to put STi bits on to enhance your car, just dont badge it up to pose as an STi.

Black or white rims will look great, but white will get dirty quickly.
18's will look good, but just remember that the larger the diameter wheel you go the more expensive the tyres will get.

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[COLOR=RoyalBlue][B][I]Titanium Reinforced[/I][/B]
MY00 Impreza WRX | MY11 Liberty GT Premium[/COLOR]