This is more of a suggestion to car manufacturers than a recommendation.
I think it would be a good invention for them… there are so many different reasons to honk at someone but the honkee never knows the honkers intention unless it’s obvious. Like, if you’re driving and you notice a hazard that you want another car to avoid, there should be A well intentioned honk beep. If you want to punish someone for driving dangerously, there can be a mean beep sound. If you see someone you know or want to signal neutrally to someone else, non driving related, there can be a greeting beep. If there’s a protest or you drive the same car as someone else, solidarity beep. And so on