"It was shot around Eastbourne and in the middle of the film is a shot of an open-top Southdown austerity Guy Arab on the service to Beachy Head. Deborah Kerr and Hayley Mills go upstairs and travel for a couple of minutes on it. The Gardner engine is quite distinctive throughout the scene. It must have been quite an experience sampling the 5LW under-powered vehicles struggling up to the Head!" (thanks Chris Hebbron)
Kerr and Hayley Mills run to catch the bus as it's about to pull out; the sequence is notable because Mills nearly
misses her leap onto the platform and spends an age hanging off the back before she is helped to safety: