Hi Tara, yeah I thought it may have something to do with the “acid” wheel cleaners that may have been used on the car (only had the car for two months so don’t know much about it’s history ?) - that said I would’ve thought it would have affected both callipers not just one. No evident lip on the disc on that side and no visible signs of excessive/ higher temps either - car brakes straight and true ruling out a sticking calliper in my mind. Can’t imagine replacement SEAT decals available and certainly haven’t got a steady enough hand to paint in the silver ??