Yes it does get worse with age (mileage), and yes you can fix it, but not cheaply.
The problem stems from the fact that the vanagon has its center of mass behind the aerodynamic center of pressure (like flying an arrow backwards). This is inherently unstable and squirrely in cross winds.
    Start by checking the wear on every component in the suspension:
    Front:   A-arm bushings, Ball joints, Tie rods, Front link rubber biscuits. Check that wheel bearings are snug.
    Rear:    Trailing arm bushings, rear wheel bearings

Good luck, these parts are pricey..... Randy Bergum '90 Carat

Cam Murphy wrote:

My '84 Westy handles terribly in just about any crosswind situation. I have owned it since '91 and have always had the same complaint (especially at higher speeds). The problem appears to be getting slowly and progressively worse. I have been on the mailing list for approximately one month and do not recall seeing anything wrt this problem. I have talked to others and they seem to have the same problem. Can anyone tell me if this is an inherent design flaw from the beginning and/or does it get worse with age? Also are there any relatively inexpensive fixes? Thanks, CamCanadian ForcesGeilenkirchen, Germany