I have an '87 Westfalia. As you all have realized, I opened up my passenger
door to put in some sound deadening material. Behind the interior door
panel, or card, is a clear plastic, adhesive-backed sheet covering the
door's metal, presumably to keep water from leaking in. Because it's old
and brittle, it's almost impossible to pull it off without tearing it, thus
compromising the barrier. I still need to replace this on my passenger door
and want to find a source before I do the driver's side door and the
slider. Where do you get this material?

Thanks in advance for your advice!
Marc Perdue