You're missing the point of symmetrical. They are talking about colors, so one side can't be black and the other side red. It's been done in the past, but Terry Labonte's 2014 Talladega scheme where it was a Kellogg's scheme on one side and a Piedmont Airlines scheme on the other side. https://www.sportingnews.com/us/nascar/news/nascar-wont-ok-tribute-paint-scheme-for-terry-labonte/kvemhdpesnt01ohgtzbw40p12 I know it's been done it the past, but that scheme I think NASCAR said, "We're done."