i like a bit of each idea, james......

being of the "im an oddball" camp, i say get stuff that you dont see locally at all, and then put a spin on it...

eg:
the JPN wrx wing and riser,
powder the wheels with a matte finish (or at least a semi non-gloss),
and def. do the i/c (but use the correct non-absorbing paint i hear about)...
[perhaps doing a stylized outlined "P" logo on the i/c in stencil format, to give flare...]

and well, sleeper, well, you have a japan musclecar bro, with a sewerpipe sized exhaust that sounds like the PTSA metro busses around here.... i dont think you could fool the def or the blind with that beastie...

ese

ps- gimme a ringski back!