Your advice is possibly bad as well, especially in the context of MA.
I can only think of a handful of situations where "drawing to brandish" in a road rage scenario might de-escalate something, and most of them would not pass legal muster in MA, because they don't meet the "imminent danger of death or serious bodily harm." standard held within the law. That applies to ALL deadly force, not just -using- a firearm against someone.
Chew on that for a minute- if someone is actually attacking you, in a situation which justifies a deadly force response, are you REALLY going to pull a gun with the intention of not using it? Especially in the context of a road rage situation which has already deteriorated from bad, to worse, and then to really bad.
Road rage situations are a bucket of garbage and people should avoid them at all costs. Wreck your car, break draffic laws, do whatever it takes to avoid dealing with whoever it is that is harassing you. All of it will be cheaper than dealing with a possible ADW charge. They are worse than other situations because it doesn't take much for the DA/Prosecutor to spin the whole thing into "mutual combat" which can effectively take any self defense justifications off the table.
-Mike