About the cable, I suspect you might be in a road salt area so keeping the unit washed and covered when not in use will be important. The cable is galvanized so it will resist rust, I have never put anything on my cables just because it becomes a magnet for dirt. We don’t sell anything specific for cable, I would run if for a few years and see if you start to see any rust, it will turn grey from oxidation but still function perfectly.