I have a 2002 Spyder and haven't yet found the best way to clean and protect the back plastic window. The previous owner cleaned with normal sponge and standard car wash then applied standard liquid wax to protect it. I've worried about using sponge / car wash due to potential scratching. Also, I haven't used car wax on the back window with fears that removing the wax with a microfiber might scratch too. Anyone have any tips on cleaning and care? Thank you.