I'm going to replace the radio in my 88 vert and would like to keep the headrest speakers and amp intact. I can account for all but one wire in the diagram, that being the single white wire running from the radio to the headrest amp. I've searched to no avail. Any clues?

 

why do you want to keep the factory amp and speakers in the first place? REPLACE THE ENTIRE SYSTEM. Speakers are not that much depending on what brand you want to go with.