I remember one guy made one out of a warped piece of cardboard. I don't see why it would not work. I'd put together a spring loaded flip up device if you will be plowing in an unfamiliar area.
Depends on what type of plastic it is. PVC gets very brittle in freezing temps. Some Nylons may work, as well as some esters. Most polycarbonates won't do well at all.