(1959, Peter Sellers, Constance Cummings, Robert Morley)

“It was set in Edinburgh and there were several Edinburgh Corporation buses visible including a couple of Daimlers, a Tiger Cub in quite a clear shot and various PD2 BMMO-front machines, presumably the famous 'monstrous masses of shivering tin'.” (thanks Mike Lloyd) None of the buses are seen clearly, there are even very distant views of tourist coaches. Here the Leyland Tiger Cub is followed by a Daimler CV:

…and here are two Leyland Titan PD2s: