Exactly, the manufacturers only warranty rust through on panels and that it is in these climates. I have owned cars from down south with 100k plus miles and ones locally with 1/2 the miles and there is no comparison. Anything aluminum will corrode horribly, I have seen a hole ate right through a FPDM before do to its location on the 04 up F150. It sits up under the spare tire and in other climates there are no issues. But salt especially when roads are wet goes EVERYWHERE.
When I worked at the local Subaru dealer they had a subframe corrosion issue only happening in the areas with harsh winters. Toyota had PCM issues from salt corrosion too. Google it and there are many cases of it causing issues with electrical as well.