Put a couple strips of reflective tape on the inside of the door. The next time you have to pull over on the shoulder at night, open the door and you'll have a brilliant attention-getter right where it will do the most good. Who knows, it could save you from being rear-ended some day. It can't hurt, that's for sure!
For old camper wallpaper: "When Painting Over Wallpaper is the Better Option." RV remodeler suggested, paint, tissue paper, paint to create interesting new texture.