Last goodie

Installation instructions.
As you can see, there's a second harness that plugs in and goes to the rear speaker. It should be easy enough to cobble up, but I've seen someone selling reproductions on Ebay, I think.

Mr. Sinister said

What does the control knob look like and where is it located in the dash?

Click to expand...

There are several different control knobs and dash locations depending on which car you have.
Here's a few. There are more.