NASCAR fans, being who they are, will almost certainly look upon this as a challenge, and untold numbers will sneak the banner in anyway, so when the the events get underway, the banners will sprout like dandelions.
Stock car racing was BUILT on the rebellious sons of the South running illegal moonshine over the back roads and byways in tricked-out and souped-up Fords and Mercurys. The 1940 Ford coupe was a particular favorite, as was the 1949 Mercury. The Confederate North Virginia battle standard was just part of the standard equipment.
Good ol’ boys have been around a long time.
That is how I see it too, at least I HOPE that's how it plays out. Also, they are ASKING fans not to fly the flag. I think that means you don't really have to SNEAK the flag in. I doubt if Leroy at the gate is going to raise the alarm if he sees one.
It’s never a good idea to tell rebels what to do.