Salt a way is very good for recent salt. For persistent stains there is a product called "A-maz". It is available at Amazon and Home Depot lists it. Ace hardware used to carry it. This is a bio degradable paste. We were told about it by the glass shop who did our shower enclosure.
For daily use, we use a Windex, or Rain-X window cleaner. We keep the front windows coated with Rain-X. (Cannot use used on plastics, but there is a specific plastic product.). Salt water runs off well with the Rain-X.
For the side window "handle/latch". I have used epoxy and the "glue" used for rear view mirrors on windshields. The handle and the glass has to be very clean, and then wiped with isopropyl alcohol. The new ones come with a pad which which is a double stick tape. Works moderately well.