Last weekend I was able to confirm the consensus of the list about
installing a '99' programmable intermittent wiper relay in a later model
Vanagon, '90 GL Westy.  Plug and play.  Took me longer to get the cover back
on the fuse/relay block than it did to do the install.  And, being in the
Great NW, the weather obliged from Vancouver, Wa. (that's across the river
from Portland, Or.) to Seattle, several hours drive in varying but steady
rain to test it out.  Works great.