I saw them on the construction workers trucks down here in SD who were remodeling/changing/whatever various business park locations where I worked last round. Nobody messed with them.
I had someone in Redwood City rip my 'support the troops' magnet in half that was on my car back in 04.
I finally saw a Biden sign stuck in some middle aged woman's window. Happened too fast to get a snap, but she was driving a 2005 era Sedan of some kind, looked like a "typical teacher/librarian". It happened in Brevard, of all places. Of course, hugely outnumbered by the Trump signs in every other business along the road.
No scratches or smashed windows on the truck as far as I could see. My guess is this guy is visiting from the central valley or just plain stupid.
No Biden stickers found so far, stll.. I have been looking for two months now. That is how I spotted this guy.