easy way to repair plastics is from behind. Get a good two part epoxy and a an old rag. Cut a strip of the rag so that it is 1" bigger than each side of the crack, like a band aid. Put your two part epoxy on each side of the crack, lay the piece of rag into the epoxy then epoxy over the rag. When it dries it will be super strong and you wont see the rag because it is on the under side of the plastics.