Northern can't make the windows of their 156s even see through, what hope for a clean train, let alone a refurbished one? Please Northern leave us and let someone else run the services. I didn't like Arriva, but the trains were clean and they painted stations - hideous colours, but fresh paint and washing seemed to work!
Heaton seem to keep the 142s windows clean but the 156s are fitted with brake dust brown glass, not at all fetching. The glass colour makes even the Northern livery look attractive, if you can see it beneath the grime.