More Examples:

I see this everywhere. Hidden or transparent monochrome American black flags on large trucks or 4-Runners. Usually speeding or driving aggressively on the highway.

I found this:

The black and white American flag originated during the American Civil War between 1861 and 1865. It was created as an opposing symbol to the white flag, which symbolizes surrender. Confederate army soldiers flew the black flag to demonstrate they would not give in or surrender to the enemy. It showed that they would rather be killed than taken in as prisoner.

And this:

Sometimes soldiers show respect for their country by using the black version on their vehicles

My question is for the people doing this. What message are you trying to send? Are you openly telling your coworkers and neighbors that you are still supporting the South in a war that ended long ago? Are you low key showing your support for Trump? Are you ex military showing support for your country? I ask because at least for me, the message is unclear.