Greetings from Colorado...

That piece is the adapter which fits onto the bottom of the antenna mast, which claps the antenna securely to the slope of the nose of the Vanagon.  If I recall correctly, this is accessed by reaching through the door jamb when the drivers' door is open.  It's easy to drop and it tends to vanish into the abyss.  If you antenna is still properly attached, somewhere down the line somebody was replacing the antenna and lost the one you found.  It finally escaped into the open air!!
--

*Best Regards,
Jon B Kanas
Email: kanas@qadas.com <mailto:kanas@qadas.com>
Longmont, Colorado
Website: http://www.qadas.com/~kanas <http://www.qadas.com/%7Ekanas>

Nothing doth more hurt in a state than that cunning men pass for wise.
-Francis Bacon, essayist, philosopher, and statesman (1561-1626)
*

Date:    Mon, 17 Aug 2009 10:09:02 -0500
From:    Max Wellhouse <dimwittedmoose@CFU.NET>
Subject: Re: What is this part/piece?

Maybe that piece that helps support the radio antenna on that steep
angle under the dash?????  Yeah, I know it's a stretch.....

DM&FS

At 07:03 PM 8/16/2009, Jim Felder wrote:

> >Not a vanagon part, I don't believe.
> >
> >Jim
> >
> >On Sun, Aug 16, 2009 at 6:55 PM, Robert Fisher<refisher@mchsi.com> wrote:
>
>> > > My wife has been driving the van today, which may or may not have anything
>> > > to do with anything, but when I got in a while ago this
>>
> > piece/part was lying
>
>> > > on the floorboard in front of the driver's seat.