Least expected. In the less-nice side of town and this black gentleman comes up to me and says "is that your Miata out there?" I'm like yeah why? Figuring it's a car guy. He says "where we go one we go all!" And we exchange info/stories. Crazy!
Edit: I have a bunch of Trump stickers on all sides and https://GreatAwakening.win on the back of my car, for clarity.
My best was in a neighboring town when a car stopped behind me at the light. I looked in the mirror and the people were holding up 3 fingers, making a W and pointing at my WWG1WGA sticker on my windshield. I clapped and then put up my 3 fingers.