[Formulabruce]

The quarter panel side brackets sat on 4 "Paint insulators" as we called them at the dealer. One for each bolt, 2 per side.
Factory ones ( you can see them in assy manual, and Parts too), were a thin foam. These did do the job of protecting the factory paint the first time bumper was installed.
The big clips on these side brackets can easily make a deep scratch and let any water to the metal ( even a hand wash in driveway) .
A couple remedies I have used are Electrical tape, and Gorilla tape cut into squares. The originals were a slight sticky back.
We had a roll of whatever GM sent us, but it was about as rugged as the foam.
SO, If you have some fresh paint, I would recommend Protecting it!