BadHabit2Break
forum member
I think I found the answer to my question above. It looks like the shelby spacer is 1/2" wide but due to the cutouts that it has if you use 1/2" mdf that is not enough by 3/8' inch. So you can't use 1/2" mdf. Looks like 3/4" will be enough though.
The stock wiring harness has 4 wires and I'm assuming you are using all 4 of them with these speakers. Can you summarize how you wired it up?
The wiring is simple. 4 wires (2 negative, 2 positive).
http://iihs.net/fsm/?dir=710&viewfile=130 - Audio System and Navigation.pdf
Page 2 and 3 depending on your build. Door sub wiring looks to be the same though.