Trick is/was back in the old days of old gas burners, 6 volt electrical systems, poor heater/defroster, and NO WINDSHIELD WASHER, you improvised....
The plug of tobacco, one end opened, and painting the wiper area pattern will clean a windshield of the oily streaks like no other. And as you move on down the road.
It you are stopped for a while and need to clean it; with it wet, just wad up a fist full of newspaper and scrub it down to dry. The ink in the paper does the action, like the tobacco does its thing.
The Coca Cola bit.. Get a hot coke/pepsicola/Dr pepper/etc, shake it up till it spews past your thumb over the opening, and spray the windshield with wipers going.
Get cola in plastic bottles, as the old glass coke bottles were hell on windshields if dropped.
You could stop at any space available; grab the plug out of the glove box, open the door, reach over and smear the driver side, get down and walk round back to see if all the bulls were still standing,
come up on the other side ,do it, crawl back in and be gone down the road making more nickels.
Just for kicks, get you a plug, bottle of Coke, and a couple of sections of news paper and put in your car/PU or truck. Next time it rains, use them instead.
If it works, ask about improvised defrosters and trailer light grounds.
