In a message dated 99-02-15 14:16:26 EST, steeling@CREATIVE.NET writes:

<< here are two sliding windows on my vanagon.  They can't easily get
 popped out of their track because of a plastic spacer that keeps it
 tightly into its frame/track.  So what do you do when said plastic
 spacer gets old and crumbles away and needs to be replaced?  I've done
 some looking around, but know one seems to know how to get a
 replacement.  Surely someone else on the list has had this problem.
 I've done some looking around at my local parts junkyard and other
 sliding windows there suffer from the same problem.  I suppose I could
 Gerry-rig something, but I'm not particularly good at that sort of
 thing. >>

you can still get them from the dealer.
YES YOU CAN :<)

chris