Hi Donny,
First, in '89 when I started my restoration my quarter interior panels were water warped where meeting the floor. To address the recreation of the panel, I used an 1/8" piece of plywood called a "Door Skin". This seemed to be as close to the original plywood base as I could find. To reduce any chance of water destruction, I first sealed the plywood with a few coats of deck sealer that also served as a base for contact cement.
To date, the panels are as first constructed, however, the contact cement has not held as well. It seems that heat induced plasticizer (the chemical that makes vinyl flexible) migration causes most contact cements to become gummy and non-adhesive. This condition has developed with all the contact cements I have tried, however, does not seem to happen with weather strip cement.
Also, for my doors, knowing I have a tendency of leaning my knee against the panel and causing a deformation, I chose a very hard and water resistant tempered masonite created for bathrooms. Again, I applied a sealer as a base coat and glued a thin layer of foam under the vinyl cover. Since this panel material is extremely hard, staples are not an option.
Hope this helps.
Ray (64BJ8P1)