peanut butter!!!
ok, when your done laughing, getting paper stickers off plastic, once you tear the paper off, and the stickem layer is still there spread some peanut butter on it and let it soak. after a couple hours wipe it off with a paper towel. no scratches on the plastic. I used this trick to get the residue off a company truck after i pealed off there logo. it dissolves the sticky somehow. I could still see the logo because the surrounding paint was a bit faded, but no glue! I use this trick on plastic fly boxes, works like a champ!