This might not be completely true, but I was told by a former cop that technically anything obscuring the driver’s view through the windshield is something they can use against you. Hanging air fresheners, bobble heads, a mounted dash cam… it’s just one of those things that isn’t usually enforced.
Oddly enough, it’s not even that far off from what really happened:
https://www.thegamer.com/lets-talk-about-that-infamous-lord-of-the-ring-cherry-tomato-scene-with-denethor/