Hello, I've just come back from a driver today and had a look at my rear callipers. For the last couple of days I could hear a ticking noise, and upon inspecting, it looks like the protective coat had some off and was stuck between my wheel and calliper causing the noise, which is fine since I have now removed it. However I have noticed that the callipers presumably metal casting is now exposed. Braking is fine, but should I be concerned about this? What should I do to ensure they don't erode or become (further) damaged? Any advice would be great, thanks in advance. I have uploaded some image and videos of my two rear callipers. The front ones are fine. Rear Calliper 1.mp4Rear Calliper 2.mp4