I haven't installed one yet, but I'm researching it right now.  The only
source that I know of is ADDCO. http://www.addco.net/ . I'm considering
making my own out of chromoly tubing and adjustable arms.

You're question "does it help to keep the rear wheels planted when cornering
hard?" sort of misses the point.  In pure theory an anti-roll bar will
actually cause the inside rear wheel to lift and spin in a hard corner. The
advantage is that a rear a/r bar will shift the "roll-couple" or roll
resistance to the rear wheels, causing the rear wheels to carry more of the
cornering load.  This takes this roll resistance load off of the front
wheels allowing them to turn the van more effectively.  In practical terms,
you'd be shifting the van's designed-in tendancy to understeer (plow),
toward a tendancy to oversteer (spin-out).  If done moderately leaving the
van's cornering balance closer to the neutral range, this shift can make for
a fast vehicle in the corners.

One caution though; from the factory VW set up the Vanagon with a lot of
understeer for safety reasons. With the engine in the rear, a shift of the
roll-couple to the rear can create a situation where the van tries to
spin-out at the worst possible time (in a fast corner, realize you're going
too fast, take your foot off the gas...there she goes, your in the trees
butt first).  Test your setup a lot before you trust it.  A wet, smooth,
empty parking lot is a great place to try to lose the rear in a corner just
to find out how easily it happens.

Get it right, and your Vanagon will be a lot more fun.

Gary
----- Original Message -----
From: "Joe Tu" <joetu@PACBELL.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, April 09, 2002 4:33 AM
Subject: Benefits of a rear sway bar?

> Anyone who has one installed give me some feedback on this, does it help
to
> keep the rear wheels planted when cornering hard? Where does it mount
> exactly and who makes these for vanagons?
>
> TIA!
>
> Joe