Just a question that always puzzled me.
Agatha Christie often mentions the cars that people are driving and she always uses existing brands and models, like Bentley, Daimler, Austin, Morris, etc.
Poirot never owned a car, he always travels by train and taxi, and sometimes he is seen in a hired Daimler with driver. Except for one story, where he actually does have a (very) expensive car: a Messaro-Gratz.
However, as far as I know, there has never ever existed a car of that brand.
Why has Agatha Christie in this single case made up a non-existing car? Why didn't she give Hercule Poirot a Rolls-Royce, or a Hispano Suiza, or another expensive and exclusive car that existed in the real world of that time?
Being a car-lover, that always puzzled me. Who knows the answer?