RE: CB in the Vanagon
Right after I bought my '90 Westy I installed a Cobra 75 (Google on that,
lot of info out there), runs about $100 or less if you shop around.
Everything in the handset/microphone.  Only have to install a small junction
box where the power, microphone and antenna come together.  Later I
installed a good antenna at the right front of the van because the gutter
mount antenna I was using was not very good.  Mine is set up on a center
console I have between the front seats.  Over time I've found I use the
Weather Service receiver  more than the CB.  I can only remember a couple of
occasions using the CB with other Westy drivers, one recently.  I do turn it
on to listen to the truck drivers if getting into heavy or slow traffic when
stuck driving the freeway.  For travel with other VW vans or buses the
little FRS transceivers work very well.
As for location for install that's going to depend on your expectations and
taste.