I am building a triangle box. In the pic, the front of the bike will be to the right. The motor is on the frint wheel. The four "T" marks you see are attachment points to the frame (OEM spots for air pump and water bottle rack). I want to make the final box from the flexible but strong black plastic that I use for mods on my car. I might make the sides with fiberglass over these cardboard templates. Any pointers about waterproofing? Or anything else about this kind of project? (Btw, The battery is sealed in plastics and will be cushioned so it cannot contact metal surfaces.)