Ricardo Reyes and Elon Musk, from Molly McHugh’s piece in Wired (emphasis mine):
“In other cars, all the systems work separately—there are different processors for different parts: the safety system here, the cruise control here,” says Reyes. “And that’s the evolution of building cars in stages, whereas our car has a central operating system, more like what your phone has.”
“Car-makers need to think of their cars as connected devices, that the way a car should operate, like your cell phone or laptop so you can do improvements over the air,” says Musk. “… It’s important for safety and functionality that car-makers move to a connected philosophy … It’s kind of odd to have a computing device that’s not connected.”
You can be sure that if Apple chooses to do a car, these are key philosophies they will incorporate. Apple is all about integrated hardware and software because of the superior experience this provides. It’s very possible they can just come in and built a better car than most manufacturers.