In the scenes depicting young Lazenby driving around England, the car he is driving is left hand drive. The UK uses right hand drive vehicles.
A suitcase of £20 notes would not have been possible when this film is set. The £20 note had been discontinued between 1945 & July 1970. The £20 notes seen here were issued from 1991 until they ceased to be legal tender in 2010.
When George first enters the car dealership in London, a US flag flying on a pole is reflected in the door glass (and the door is noticeably American in design). Later, from inside the dealership, three US flags can be seen flying on poles outside.
It has been pointed out that the car driven to Bristol is left hand drive, but it is never clear which side of the road it is being driven on except that he parks at the kerb to pick up his girl, he may just be polite. It is common to drive imported LHD cars on the left hand side.
In 1964, George is working as a car salesman in a Mercedes-Benz dealership with a W114/115 series car in the showroom. First ones of this make rolled out of the assembly line in December 1967.
When depicting the route that Lazenby's ship takes from Australia to England, around the 26:20 minute mark, the country of Sri Lanka is shown in the wrong place. In actuality, Sri Lanka lies below India, and not to it's side in the Bay of Bengal, as depicted in the map.