I don't think Apple is interested in building a car at all -- but I do think that they are interested in being the brains of the driverless and semi-autonomous cars that are on the horizon -- maybe a slightly different approach than Google is taking. As cellphones become even more powerful, and are already being integrated into newer automobiles (Apple's CarPlay, or Android Auto for example), wouldn't it be natural to utilize your phone as the hub of the driverless car? It can already communicate wirelessly and transmission speeds will only increase over time (although I've read that current cell connections are not fast enough to support car-to-car communications, but that will rapidly evolve). Not only will the phone be tied into the autonomous driving system within the car, and interact with the other cars, but will also support all of the sensors that deal with engine, drivetrain, and onboard computer (no more "check engine" light, but a complete description of the issue and what it takes to resolve it -- although there are apps that will do some of that today).
If Apple can integrate itself fully into the automobile from the sensors and wiring harness outwards, then it will have almost completely immersed itself into our lives. Even older cars would be able to take advantage of some of the car-to-car networking capability -- just download the app and go! Which also makes me wonder why they are selling wifi connected cars? Isn't the car already wifi enabled once a person with a smartphone hops in?
And if all of that isn't exciting enough, now Elon Musk/SpaceX has announced plans to build a prototype Hyperloop (does that guy ever run out of ideas?). I'm hoping that enough resources will be thrown at that to derail California's bullet train, which seems to be focusing a LOT of scarce resources on a project that will take years, and will likely be obsolete by the time it's completed (if ever). So aside from teleportation, a lot of exciting transportation options (and one not-so-exciting option) are on the horizon!