Story I heard, was that Hyundai hired away many high-end QA people from Toyota, and because there's no intellectual property treaties between Korea and Japan, there's really nothing Toyota could do about it.

They apparently even took plans, detailed documentation, endless amounts of information to Hyundai. I'm not sure of the veracity of that information, but it sure explains how Hyundai became incredibly good, literally overnight.

They used to be a joke.