A survey is sent to car buyers with a huge number of questions related to their satisfaction. Automakers, Tier-1 suppliers, and probably others get to buy this data to mine for market research.

At a past role with a Tier-1, we bought part of the dataset. A quick regression showed that satisfaction was strongly correlated with buyer age, and there was very little signal otherwise. (Young people with overtime work and daycare pickups don't respond to surveys unless they have a serious axe to grind while retirees aren't so constrained)

Problems reported in the first 90 days of ownership. Overwhelming minor niggling complaints like a piece of trim making a noise or even just misunderstandings about systems.

American automakers love crowing about that survey because it's easy to do well on. And then the car falls to shit six months later, but hey, it held together for the first 90 days so all good.