That plastic is a moisture barrier. It keeps any wetness that may get into the door away from the door panel. Remove at your own discression. You could always replace it with something else if you need to (like some some drop-cloth for painters, etc.)
Ok, so it looks like I have to use my current window switches with my new door panels that just showed up. Problem is, I can't figure out how to take the switches out, I took out four screws so far, and there is obviously some clips that hold it in place, but I can't get it out.
Yeah, I figured it out. Good looking out guys/gal. I'll get picks up later, I was only able to put the front two in for now, I gotta go take my girlfriend to work (she wrecked her Cav yesterday). Thanks again.
Sorry Super that I did not see this earlier, I could have told you to check out my "Touch of Blue" thread on the old forum. I think I listed everything needed to take the panels and door/window switches off in that thread. But it looks like you figured it out.