Imagine it's the other way around. I'm sure Apple has been working on car tech for far long than Samsung, but Samsung has been working on it because Apple is.

While Cook is mentioning it officially today, as you know they have been hiring countless people from the auto industry for many many years as they work on the tech. AI is integratal to Apple across all their product lines so makes sense to also do AI for autonomous systems such as a car. Apple isn't saying they will build their own car necessarily, they are saying they would build the underling tech for the car, that they would then presumably license to luxury car makers.