interesting triva Richard Petty ran the 1968 Daytona 500 with a mystery black top Roadrunner
quote from a NASCAR site
"It's become folk-lore that the car had a vinyl roof. That's not the case. It was textured black paint. Call it the golf ball theory of aerodynamics. The "pockets" in the textured paint were supposed to capture air, which would allow the passing air to move more efficiently over the car at speed. Think about it as air sliding against air, instead of air sliding over the sheet metal."
During the race, the roof began separating from above the windshield frame.
Some said it was acid dipped or aluminum roof
They duck taped down to finish the race