s '87 gl stereo cheap fix ?

Some of the BlauPunkt radios have the facility for an aux input via an
accessory cable.

A simple setup would be the Blaupunkt Reno (used ~50$), a BP cable ($15) and
for the ultimate mp3 music storage the MPD-01 that uses a IBM/Hitachi
microdrive and acts like a CD player controlled from the Reno cassette
player (useful for books on tape to override the noise of the passenger side
airbag).  With the second aux input one can also attach the output of the
cave rat special or Sirius doggy-style satellite radio.  BTW thanks to
caverat, I snapped up some Sirius at ~2 and let it go for ~7.5 healthy
capital gain there.

I can mail you the specs on the Blaupunkts mentioned above.

Reno has a remote control facility and accepts the 'thummer' and credit card
remotes.s

You could be back in business with a removable face, remote enabled,
cassette+mp3 player for say $200.  The Reno and the Aspen and the Sydney all
style match the instrument panel of the vanagon much better than today's
offerings of doodahblingblitz styling to attract the undiscerning eye.

If you live in an area with few FM stations an FM modulator from RatShack
will provide any acceptable link to any FM set indoors, outdoors or in
someone else's conveyance.

Adding an additional amp under the drivers seat will allow powering more
substantial speakers should you feel the need for fidelity without the
womp-womp.

I can mail you the specs on the Blaupunkt gear mentioned above, or you can
search and download from a BP outfit in the UK.

With the out of sight out of mind characteristics of the MPD-01 and the
unattractive-to-thieves cassette player you may be on the way to a theft
resistant system, unless you live in BenT's area or YewNork or los barrios
or SS Chicago or Detroit or Miami or Houston or Atlanta or...