I would highly recommend JL Audio or MB Quart speakers in the factory
speaker slots.  It is easy to take the factory grills and make them
work.  I used JL Audio 2-ways TR400-CX in all four slots and added a
subwoofer under the rear bench.  The tunes sound awesome, especially on
the freeway with all the wind noise.  Just make sure whichever head unit
you choose, that it has equalizer adjustments.  The Pioneer unit I have
lets you adjust bass/mid/high as well as choose the frequency point of
each and the sharpness of the curve.  This allows you to make the sound
very smooth through the whole dynamic range.

Here are some pics.

http://www.ctsr.com/vanagon/page_01.htm

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of siperek
Sent: Monday, July 05, 2004 11:33 AM
To: vanagon@GERRY.VANAGON.COM
Subject: stereo install

i would like to upgrade the head unit and replace the 4" speakers and
maybe add a little bass in my 91 westy.. not for showing off, but for
cranking tunes on the road trips.. im sure  alot out here have done
this,  any pictures and suggestions would be great.. especially on how
and where you added your subwoofer.. and how and where you ran the
wiring.. thanks  scott.. 91 westy boston.