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.
As mentioned by a few other posters in this comment section, that’s not the only explanation for the use of that color scheme. In my opinion, it’s also not the most likely explanation. I believe this is a case of veterans who saw and wore the monochrome flag due to it being a uniform item for situations where full color would not be appropriate. This is why you’ll find brown or black versions of the shiny metal insignia that an officer might wear in the field: a sniper picking targets would be smart to seek out people in leadership roles to maximize the chaos following an attack and shiny metal stands out. Also why you don’t salute officers in those situations (unless you don’t like them and want to see if there’s a good marksman on the other side paying attention).
Once back in the real world, some of those uniform items might end up as a decorative touch on bags or around their homes where they’ll be seen by friends, family, coworkers, etc. and might make their way into general use. For most people, that’s going to be how they’ve come to know things like the flags highlighted by the OP here and it’d be a mistake to read into it much deeper than that without other indications (e.g. southern traitor flag).