I forget the name of the subreddit but it's called like "schizo cars" and there are a ton of examples like this. They seem to be mostly people with mental issues.

This is usually associated with someone with mental health issues. Either they're so far in the deep end of conspiracy theories that they think everyone else has to "wake up", or they've go no social filter and they just dump every thought onto their car.

There's always a few lines that tip you off to the mental instability. Either deliberate contradictions (like this one with "police state" and "blue lives matter") or there will be one that pushes it into the deep end somewhere (like a "...and THATS why there's lizard people in the government")

Either way, usually the people with cars like this very much need help, and very much won't get it.