You're demonstrating the problem with speaking overly generally.

I too "find it within the realm of acceptable that a $30,000 car would have issues that should absolutely not be present on a $100,000 car". If, say, a plastic piece on the dashboard tends to develop an unsightly crack over time, that's more ok for a $30k car than for a $100k car.

But some design issues should be present on no car; not a $30k car, not a $100k car, not a $5k car. "The car sometimes accelerates on its own" is one of these.