would I just tap into the stock wiring for my spoiler brake light? it's a stock SE spoiler /w light.

 

just find the wire in the rear light assembly (tail, blinker, reverse) that gets power when you tap the brake
splice a new wire into that
run that wire up the trunk hinge and under the trunk lid liner and connect it to the spoiler brake light

easy peasy

 

or just use that wire because it looks kinda wierd with both on.
or you can just buy my gxe and you wont have to worry about it :d