Man Bait AKA The Last Page (1952, George Brent, Marguerite Chapman, Diana Dors)

Despite the opening credits this was the 16th movie made by Diana Dors. The aforementioned credits display in front of footage of London traffic, including a tram and a 'prewar' 2RT2 AEC RT:
Two buses identifiable are RTW212 (KLB942) and RT2097 (KXW206):