(1932, Leon M Lion, Anne Grey)

Early Alfred Hitchcock thriller features a chase between a train and a canvas-roofed private hire London Passenger Transport Board Green Line coach. Originally spotted by Colin Read, it was reported to me as a T-class AEC Regal, but both Bob Wingrove and I believe it's actually a much rarer 1929 R-class AEC Reliance:

There are brief interior shots:

As the chase nears its climax there is much use of models. The model bus used does appear to be based on a T-type AEC Regal. The full size bus has a canvas roof and front and rear doors; it has 'London' would up on its destination indicator. The model has side route boards on the roof and an open rear platform; it has 'Brentwood' as its destination: