I used two of the mounting cups from
http://www.bus-boys.com/bbvdo.htm#cups.  I mounted them on the dash next
to the ash tray.  Expensive, but looks good, and you could squeeze three
in there.  I can send you a photo if you like.

Here is another option that might work--an A pillar pod:
http://egauges.com/vdo_agrp.asp#A-Pillar
Nothing listed for the Vanagon of course, but you might find something
that will work.
--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Daily driver since 1969)
'74 MGB GT (Restoring sloooowly)

Personal mechanic for:
'70 MGB GT (Daughter's)

Assisting on Restoration (and spending OPM):
'72 MGB GT (Was daughter's, now son's)
'64 MGB (Son's)

Stripped and gone but their parts live on:
'68 MGB, '73 MGB, '67 MGB GT