I got this spoiler off a 98 sedan and put it on my coupe and took the connection from my rear dash third brake light and plug to the spoiler.

My question is; is it possible to get both spoiler brake light and third brake light on the rear dash to work together and how?

 

Sure. You'll just have to splice some wires. Wire them in parallel or they'll be dim from splitting the voltage. Positive to positive, negative to negative.

Did you grab the harness and the springs too?

 

yes I got the harness with it. And the one from my dash is still there too.