My 2013 Ford Mondeo estate has been sitting on my drive, on a SORN, for the past five months. Consequently, the brake discs have developed surface rust. Will the rust rub off when I put the car back on the road or should I clean the rust off manually? I ask particularly as a neighbour had similar rust, though under different circumstances, that embedded in his brake pads necessitating complete replacement of his discs and pads.