i got a after market spoiler today ...the spoiler come with 2 wires<black,black+red>.however ..my 2000 coupe has 3 wires from brake light<green,black,black+red>.....so i not sure how to connect them properly....?????
what is the green one stand for?

 

Why not wire the third brake light on the spoiler with the third brake light in the back window. That's pretty much how it's wired on the factory spoiler.

 

green is a universal ground. your black, black/red is your +/-