If necessary, it is OK to signal to the subject motorist that he is "number one" in your heart, but never get involved in a conversation in traffic, unless you're certain it will be a friendly (or at least a neutral).

If you choose to roll in the mud with pigs, you both get muddy & look a little dumb in the process. My recommendation is to keep your bearing, maintain your dignity, and ride your bike.

Semper Fidelis.