The real problem is owners do NOT wash the Engine bay monthly,its a myth that washing the engine bay is harmful, if it don't start its BC poor covering or leaky terminal, both are easily fix-able. I have been washing my engine bay in every commercial personal vehicle I have own for 30 Years 1 to 2 times monthly at the shop
http://biocleansystems.com/# their no reason not to wash the engine bay at any drive thru self serve monthly during winter and twice during the summer, (OK lazy maybe).
The chloride that MNDOT uses is more corrosive then salt and works longer at -0 temps ,if the terminal pins are not tight the chemicals corrode the connection. The way that can looks its only time before some harness connection fail.