I am in the middle of finishng my basement out and now seem to possibly have a problem. When I framed the interior walls I use 2x4's with a plastic sheeting as a vapor barrier between the interior walls and the concrete wall as instructed by a builder friend. I was planning on now insulation with r-13 fiberglass insulation. Now from reading this forum and doing more research I seem to have made a mistake. My house is 8 years old and has never had a water problem on the inside. I waterproofed the walls while it was being constructed both inside and out and it has an excellent foundation drainage system. I sit on a very sloped lot (drops 10 ft. in 30 ft.) and there is a 10 ft. covered porch around three sides of my house, so the ground stays very dry next to the house except for the backside which seems to get very little rain based on the position of the house and the direction in which most of our rain comes. I have read that I should now put xps board on the concrete walls but I can only do that now by removing the plastic (would have to cut it out) and then glue the foamboard between the studs, the walls are already wired. Could I just cut the plastic and stape it back to the studs then glue the foamboard or should I completely remove it? I don't need a whole lot of r vaule here in Georgia so I'm more concerned about any possible dampness or mold in the future.