To me it doesn't seem likely that Apple can do to the car what they did to the smartphone. It is such a strange "me too" move that it's almost as if a big shareholder or some exec saw one of those Apple stickers in a car's rear window and decided it would look better as a real badge. Apple's value add isn't immediately clear, that's for sure.
Apple's value add is the same as it has been since the very first iPod: User Experience. Apple is a UX company; they've been successful because everything they did was laser focussed on the UX.
Right now buying and operating a car kinda sucks in a lot of ways [0] because GM doesn't have anyone whose job it is to subordinate all business functions to UX. Steve Jobs did that at Apple and maybe today somebody is still carrying the torch. The fact that Apple has a culture of design and implementation oriented around UX is the value add.
Imagine the process of purchasing and repairing your car feeling like an Apple store. Imagine Jony Ive designing the fit and finish of the car hardware, inside and out. Imagine a center-console human interface that was designed by someone with taste [1]. All of this is going to be packaged seamlessly with that beautiful attention to detail in subsystems integration that makes my grandma want an iPad, just because it feels amazing, even though it does literally nothing useful.
Obligatory disclaimer: For political reasons I strongly disagree with Apple's walled garden philosophy, and it makes me so angry that the best laptops available run closed source OS's natively. But I have to admit that Cupertino's hardware, shopping process, and unboxing experience is beautifully designed, and that their focus on UX does lead to a nice experience if you stay within their ecosystem.
My user experience when I step into any future autonomous car will be the same as it is in the present autonomous (or non-autonomous) Uber - my smartphone.
Around a decade ago when I was an Apple intern (pre-iPhone) we got to go to a Q&A session with Steve Jobs. One of the questions was something like "What other products do you think are badly designed / could be improved?" and I remember him mentioning two products, phones and cars specifically. I don't really have any idea what Apple plans to do there either, but at least the interest there probably isn't new...
