Rear speaker (click images for larger view)

Rear speaker in catalog
Rear speaker in catalog
Rear speaker shown in U.S. dealer accessory catalog. Catalog dated 1968.
Greg's speakers
Greg's speakers
Standard dash speaker at top, extra rear speaker at lower left. Fader control (with knob taken from a Sapphire IX) at lower right. Where on the dash, exactly, is this control supposed to be mounted?
Different speaker (1972)
Different speaker (1972)
This is from a 1972 U.S. dealer accessory brochure. It's a different design from my earlier, oval-shaped speaker.
Installation diagram (later speaker)
Installation diagram (later speaker)
This is an installation diagram for the later rectangular Sapphire speaker. The Super Beetle sketch on the right seems to suggest a "big dash" model car. The fader control is mounted to the left of the driver for sedan & super... but just where was it mounted? And is it the same location for the earlier, oval-shaped speaker kit?