If you think designing a chip with 100 million transistors and getting them all to work properly and testing to be sure they all work properly is easier than designing a car because a car has moving parts, you're just dead wrong. The quality control efforts, including things like design-for-test, fab controls, test structures, BIST, scan chains, etc. that go into making sure each of those 100,000,000 transistors work properly are far more effort than goes into QC'ing a simple mechanical system like a car.
And Apple products do "just work." Saying that this truism is wrong due to a temporary glitch (already fixed by today's OS upgrade) is like saying Macs don't "just work" because if you drop them down the stairs they stop functioning. That's not what "it just works" refers to; it refers to the fact that out of the box, without ever having to de-install crapware and install anti-malware solutions, you can do serious work with a Mac, and that when the average person tries to tell a Mac to do something, the Mac behaves as the average person expects.