Try www.partsvoice.com.  They run the dealer parts system for VW and several
dealers are listed as having this part.

Tom Young wrote:

I'm looking for the boot the covers the guide pin/rear shift linkage
connection near the transmission, part # 251 711 167A.  None of the internet
retailers I've contacted have it and according to my local VW dealer no
warehouse in the U.S. has one either.  I thought I might take a flyer and
try to contact a Germany-based retailer for this part.  Has anyone tried
this, and can anybody offer any URL's where I might try my luck?

Stuart MacMillan
'84 Westy w/2.1