I just smile, nod, and say “will do”.
I’ve been bike commuting since 1975, so I’m aware – and awareness is key. Its something not everyone has (I cringe when I hear of people dying of the right hook). That said – everything changed about 15 years ago when cell phones got popular. Suddenly it is as if 10% of the drivers are drunk drivers. I tell my kids that they have to ride like people in cars are trying to kill you – as there is not much difference between someone on a cell phone not paying attention an someone who is trying to hit you. The results are too often the same.
So, I avoid routes with traffic as much as possible (unless I’m riding the same speed as traffic), and I always use a helmet mounted rear view mirror.
And oddly, Cars treat me more like a human when I’m wearing street clothes and no helmet, vs wearing lycra and a helmet. Something about the traditional bike outfit removes our humanity.