Apart from rear brake lines that mysteriously rusted away —
Does the highway dept use Magnesium Chloride to melt snow on the highways?
It is nasty, corrosive.
I don’t think they do, and I have not had the problem on any of our other vehicles.
Based on my on-line research, there have been a LOT of cases of Silverados (primarily early- to mid-2000’s models) having brake lines rust away. As of yet, GM has not acknowledged it as an endemic issue justifying a recall.