Atonement
(2007, Keira Knightley, James McEvoy)
Four (postwar) AEC RTs appear in a London scene, three in predominantly red livery (two with roofboxes) and a fourth in wartime red/white:
One of the red RTs is rare Saunders-bodied RT3062 (KXW171), which also appeared in Murder on the Homefront:
The wartime-liveried RT carries registration 3764MT on the front, but the rear plate, KXW212, identifies it as RT3103. (thanks Steve Way, who notes the filming date as 29 July 2006)