In Germany all cars have to be checked by an independent authority for road safety every two years. TÜV is the best known one, but there are others like Dekra.

It's a standardized test. If your car fails you have a few weeks to get it fixed and present your car again.

So you have dozens of millions of cars being checked every year by standardized criteria. That gives extremely reliable statistics.

It's worse than that. The linked article is about another article (https://www.digitimes.com/news/a20231120PD209/tesla-model-3-...) which is about a report.

The closest to a source that I can find (and read) is: https://www.tuvsud.com/en-us/press-and-media/2023/november/r...