I have the JDM foglight on my Z with the ready-to-install harness. TAke a look:
DIY:REAR Fog Light install with New harness for US spec 370Z + Radar hardwire w/pics
You can buy the harness from TheZstore (or I can show you where to go)
I have yet to get any trouble from cops because after all, it's a good safety equipment. Driving in blizzard (did that), heavy fog (did that), heavy rain etc with fog light on, you increase the visibility of your car. Therefore, cops actually likes you for that (IMO)