this looks like what you are referring to:

https://www.vanagain.com/shop/plastic-part-window-regulator/

On 8/9/17 11:56 AM, Neil N wrote:
> Hi all.
>
>  From my limited experience, and from what I've read, one common
> failure point is the square plastic piece that rides along the metal
> bracket the window secures to. Reading Alistair Bells page here:
>
> https://shufti.blog/2011/01/27/vanagon-window-regulator-repair/
>
> it seems one could make that part from a plastic cutting board.
>
> I highly doubt a company would bother making this part but has anyone
> found an aftermarket supplier of that square plastic piece?
>
> On a new poorly made window regulator I purchased from AZ Autohaus, I
> tried to transfer that plastic piece to my failed regulator. This did
> not work out.
>
> Neil.
>
>
> --
> Neil n
>
> Blog: Vanagons, Westfalia, general <http://tubaneil.blogspot.ca>
>
> 1988 Westy Images <https://picasaweb.google.com/musomuso/New1988Westy>
>
> 1981 Westfalia "Jaco" Images, technical <http://tubaneil.googlepages.com/>
>
> Vanagon-Bus VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>