Funny that you picked BYD of all manufacturers: https://insideevs.com/news/712148/byd-quality-problems-hit-i...

Year old (March 2024) article about small numbers of paint scratch, storage mold, and other minor issues in a large number of deliveries from a rapidly expand manufacturer concludes:

   But it’s too early to gauge if these quality problems are false alarms or something BYD needs to take very seriously.

(also The unlinked primary source for much of that material was the WSJ: https://www.wsj.com/business/autos/having-overtaken-tesla-by... )

Kia is famous for their warranty AND the Kia Boys thing. The most reliable Japanese brands (Toyota, Honda, Mazda, I'd say) only offer 3 years here. Warranty seems to be a marketing thing, in the automobile world.

I was in to buying Kia ev6, but canceled order after waiting 1.5 years. And it’s good thing. Because this warranty is tied to regular visits for inspection at Kia dealership. Since there is nothing to service in electric vehicle Kia will scam you with weird expensive coolant replacements and other very expensive not needed replacements.