The Clone (my suicidal orange '75 Westy) had this on the dash, and my '64 camper
came with one above the wardrobe that has a neat little flap to cover it to
avoid curious fingers and errant screwdrivers.  The nearest I can figure, since
the air pump that came with The Clone fits this socket very nicely, is that the
engineers in the Vaterland figured that a cigarette lighter (which was not
standard equipment on my '64, and I can't remember if The Clone had one or not)
was not the optimal design for an accessory 12V outlet, and thusly designed this
little socket for that purpose.  When I was in Deutschland (sp?) a few years ago
visiting the in-laws, I had them take me to a VW dealer in an attempt to obtain
plugs to fit these sockets.  We were referred to an electrical supply house,
where I picked up a couple of the plugs and a spare socket so that I could
attach this plug to any accessory I might decide to use in my camper.

Hope the Bodega Dunes thing was fun, I spent the weekend working on the '64 and
today I drove her (we still haven't named her, even after 12 years of
ownership), over the hill to work for the first time in 12 months (the tranny
started making noises on the Friday before Memorial Day weekend last year and
she has been in semi-retirement since).

Good thoughts,
terry (the shifter still doesn't work right, but it's dirveable)