Another cyclist and I stop at a stop sign, him waiting to turn left, I waiting to turn right, onto a main road (which notably does not have a stop sign).
A car traveling straight on the main road comes to a complete stop and waves at us cyclists with a "go ahead" hand gesture. We remain stopped, because the car has right of way.
Meanwhile there's a small traffic jam forming on the main street as some maintenance vehicles are waiting for the car to move so they can turn onto the side street. If us cyclists were to follow the car driver's "instructions" we would have to violate right-of-way for multiple flows of traffic.
Finally the car driver gets fed up at everyone else's insistence on following the law. Makes a rude gesture, shakes their head, and continues straight. The maintenance guys can finally turn, then the bikes.
I guess my point is: car drivers need to do a better job of following the conventions and laws of the road.