Not claiming it is perfect, but here is what I use:

http://members.cybertrails.com/~ahwahnee/3rd%20Brake%20Light%201.JPG

http://members.cybertrails.com/~ahwahnee/3rd%20Brake%20Light%202.JPG

Powered by a single wire snaked into the hatch thru the same rubber boot
that the wiring for the rear defroster uses.  Grounds at the mounting screw
at the base of the lamp (as I recall I used the existing screw for the
curtain rod).  Was a typical after-market lamp trimmed to match the slant of
the rear window.  Nice in that I can still fully close the rear curtain over
it.

I did this in the days before LEDs were widely available so the brightness
is perhaps less than an LED would offer but still much better than those low
mounted brake lights we have.

Geo Hahn

----- Original Message -----
From: "Warren Lail" <wklail@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, July 24, 2009 2:00 PM
Subject: third brake light and curious

>
> While searching the archives for the perfect third brake light setup
> (didn't find it - help me out here please),...