https://qz.com/1285174/consumer-reports-just-got-elon-musk-to-fix-teslas-model-3-braking-software/

Perfection, not prototyping, is usually how cars are mass-produced. Yet Tesla has rolled out its Model 3 line by making adjustments along the way, allowing it to get to market years faster, with fewer steps, than other automakers.

That has brought its own headaches.