* Data Inconsistency: Global production data from that era wasn't consistently tracked or reported in a standardized way across all countries.
* Wartime Disruption: World War II heavily impacted car production, with many factories repurposed for military needs. This created significant fluctuations in output.
* Definition of "Car": The definition of what constitutes a "car" has also changed over time.
To get an estimate, you'd need to compile data from various national automotive industry associations and historical records for each major car-producing country. Even then, it would likely be an approximation with a considerable margin of error.
