I had broken the plastic in mine in a few small spots. I put blue tape behind the holes as a backer and then epoxy'd the broken spots with the marine epoxy "stick" (comes in a 3-4" plastic sleeve, you slice off as much as you need, and then knead it in your hands - wear gloves! and apply it to your broken spots). It worked great. Poor mans solution to a whole new panel, but worked great, sealed up holes and the white is a decent color match, not exact, but way better than the holes that were in the panel.
Good luck.