I finally got around to installing a stereo in my '88 Wolfsburg this week.
The Pioneer deck (DEH-6500) fit beautifully, I was even able to use the rear
support (just like factory).  After hooking everything up I turned on the
radio and was greeted with music... out of 3 speakers.  After checking my
connections at the radio, I popped out the driver's door speaker to ohm the
wires... nothing.

So now the games began:

#1 - pull the instrument cluster, follow the wires.  Looked fine.

#2 - drop the fuse box, follow the wires.  Looked fine.

#3 - pull gently on speaker wires.  Didn't look fine.

I ended up with the broken speaker wires in my hand.  It looks like the many
years of opening and closing the door had worn out the wires to the breaking
point.

Now that the games were over, the fun began.  Sometimes my "do it right the
first time nature" gets in the way of sensibility because I was determined
to run the new speaker wires back through the boot between the door and
body.  Did I fail to mention that my van has power windows, mirrors and door
locks?  Lots of wires running through that boot.  So off comes the door
panel and I gently pull the boot away from the door.  I spent the next 30
minutes trying to feed a variety of items through the boot, the winner ended
up being a phone cable lubricated with silicone.  I was able to feed it deep
enough into the boot so that I could grab the end with a pair of needle nose
pliers.  Time for a pint.

After a Guinness, I used the phone cable to pull the speaker wires through
the boot and into the door.  I also pulled an extra wire through to use as a
pull if I ever need to do this again.  After 5 minutes or so of struggling
to connect the boot to the door I was finished with the nasty part.  Attach
the speaker wires, put the door panel, fuse box and instrument cluster back
on and viola, quadraphonic sound.  Okay, not really quadraphonic but all
four speakers worked (did I date myself by using the term quadraphonic).

My congratulations to anyone who has had to feed wires through their door
boot and my sincere condolences to anyone who will in the future.

Cheers,

Jeff