Dennis, I have exactly the same situation as you. There are fiberglass insulation blankets above the sill plates around the basement walls. I got some black plastic sheeting from Home Depot and installed it in front of the fiberglass. In some places I was able to stuff it in around the insulation without any fastening and in some other places I needed a few staples from a staple gun to hold it.
Here's a photo showing my black ceiling with black exposed beams and the plastic sheeting over the fiberglass above the blue-painted wallboard.
Here's a closer view of the black plastic.
