I have that. I mounted it on top of my backup camera. My husband helped me use a small wedge on the front, because it was blocking my view. Well, it resolved it and there's no more blurry image when it's raining. I really thought this little gadget wouldn't work, but it did. I highly recommend it.
As long as you have no more blurry images in the rain, then you can call it a solid investment. And it sounds like a pretty easy install. So, go for it @PaulCooks.