(2011, Minnie Driver, Robert Pugh)

A sort of musical within a musical set in a school in South Wales in the long hot summer of 1976.
A night scene features a South Wales Transport AEC Regent V in traditional South Wales red livery. However….I was in South Wales myself that summer, and all the Regent Vs were in National Bus Company poppy red livery. I'd welcome confirmation, but this looks to me like Weymann bodied 590 (423HCY):

We never see this coach (?) from the outside: