 When the vinyl wraps were taken off the Class 357 units, slight corrosion caused by water getting trapped behind the vinyl was found in the aluminium around the doors, so a bodywork maintenance and repair programme was carried out.The corrosion was treated by rubbing the aluminium down and repainting it with two-pack paint.More serious corrosion caused by water seeping in through a poorly-sealed join between panels was found behind several panels on the lower part of the vehicle bodysides, which had spread to the outside.