adhesion promoter? plasticizer?
Eastwood's Prep, Rustoleum filler primer, 3M bumper cover epoxy (and fiberglass sheeting for a backer on cracks and holes), Bondo spot/glaze putty and Eastwood's single stage urethane.
Pretty much either what I had on hand or could find at Canadian Tire and TSC. This really wasn't a "planned" project. LOL.
The Eastwood single stage I shot on the wheels last Winter over the factory clear coat is still holding; it is a pretty good product.