Re: Chrome trim pitting?
Hose down your vehicle often during the winter months helps a great deal. I hose mine down every evening after work. Takes 5 minutes.
Then on the weekends I wash it. Either automatic car wash or, weather permitting, by hand.
After taking this approach I didn't have any pitting or rusting on my 06 Liberty, none on my GC so far.
2014 Grand Cherokee Limited V6 4x4