Just to facilitate communication, I'd point out that "hubcaps" cover
only the center portion of the wheel, where the lug nuts/bolts are.
The big things (now usually plastic) that cover the whole wheel are
called "wheel covers."  Wheel covers for, for example, 14-in wheels,
will fit 'most any vehicle with 14-in steel wheels, and yes, they're
available at KMart, etc.  KMart will not have hubcaps that will fit a
Vanagon.