I bought a Super Protector Plate for my bike. It did not work for me. For some teason when directly viewing the plate from a straight on viewing the entire number is blocked, and at angles when it should be blocking the numbers I can see the numbers. I initially thought it was the angle of the Super Protector and plate. So I purchased some stainless steel hardware and spacers so that the plate angle is more straight up/down. I experimented with a variety of mounting positions. Still did not work. I have given up.
I cannot recommend the Super Protector cover to anyone based on my experiences with this product. I have taken it off my bike before I get a ticket for obstructing my plate as it isn't viewable at any normal viewing angles. Don't waste your money.