let's see... change the side reflectors to white (JDM stylez yo!!! lol jk), lower it (probably just TRD springs), exhaust at some point or maybe just bigger exhaust tips (again, if TRD offers them), paint stock rims black+red lip (time attack style)+yellow calipers, yellow film on the fog lights, carbon fiber wrap for the roof, the little part on the trunk where the scion emblem is and the middle part of the front bumper. Also change the orange lights for both front and black blinkers to white (still orange light, but not orange bulb color that reflects in the housing and makes it ugly (IMHO)) and then I'll take it from there when some actual car specific parts come out from the aftermarket industry...
Boy Racer I guess?
to each their own...