I'd wrap it instead of painting it. Wrap is easier to replace/repair when the car gets vandalized.

They probably wouldn't allow it as they didn't allow an actual General Lee car lead the field at Phoenix a few years ago.

I think the sponsors are forcing the matter. The leagues and series aren't able to give up the millions they're accustomed to receiving each year. As less people go and watch on talmudvision, the less they'll collect and will be forced to lean on sponsors. The more they rely on sponsors, the more power sponsors have.