Goodbye Gemini AKA Twinsanity
(1970, Judy Geeson, Martin Potter)
Horror movie controversial in its time for its undercurrents of incest. Brother and sister arrive in London from Heathrow aboard YLD775G, a Leyland Leopard/Plaxton of Hall of Hounslow in the livery of the Pan Am airline. At one point a British Airways AEC Routemaster complete with trailer passes in the other direction:
A London Transport AEC RT is also glimpsed:
Towards the end of the film Geeson travels by RT. It appears to be RT1554 (KGU446), but isn't clearly seen, in fact the footage of the journey is intercut with a shot of an AEC Routemaster:
YLD775G also appears in Arthur? Arthur