USA : Give the thumbs down to cybertrucks you see driving around.
I have been using this simple, tasteful gesture of admonishment against shitty drivers for years. The affect is powerful, more so than the middle finger, or even aggressive yelling. Today I gave the thumbs down to a Cybertruck at a stop sign. The driver couldn't help but roll down his window, get emotional, and yell insults.
The thumbs down is a gesture of disapproval and rejection - not anger.
The thumbs down is not obscene and can be used anywhere in front of anyone. The more polite nature of the gesture lends it more weight.
People are more accustomed to being met with anger (middle finger, shouting), than measured, level headed disapproval and they don't know how to handle it.
If someone yells at you for giving them this gesture or attempts to escalate they come off as aggressive and unhinged.