(BBC childrens' series, 1994) Episode 2.4: Buses
Opens with a view of three buses, London Country NW Leyland Olympian/Eastern Coachworks LR70 (B270LPH), a London Centrewest Mercedes 811D/Alexander and a Daimler Fleetline DMS of the Original London Sightseeing Tour:

However, the true star is the Mercedes, London Centrewest MA76 (F676XMS) operating from Uxbridge garage in Uxbridge Buses livery. Aunt Mabel has to return her books to the library, and she takes Pippin the dog with her:


She's in such a hurry to get to the library that Pippin is left on the bus and ends up at Uxbridge garage.(thanks Ewood Eddie):

There is footage of the bus being refuelled:

Scot Fergie adds “Pippin also watches the driver reload his ticket machine.”
Seen passing through the bus washer is Centrewest M374 (GYE374W), a MCW Metrobus in Uxbridge Buses livery:

As the driver sets off to return Pippin to a worried Aunt Mabel, one of Centrewest's surviving BL-class Bristol LH6L/Eastern Coachworks is glimpsed in the background: