Just wanted to chime in here and say that Apple CarPlay would be a tremendous addition to my Model S. (Or, if for some reason it's not possible to add, I hope Tesla would consider its inclusion in new models.)
My phone is the center of my life, and it's so much more convenient to have the car honor that (as my wife's Honda does.) Not to mention that I have found Apple Maps' routing to be significantly better than that in even Tesla's newest Maps upgrade.
My Model S is the best car I've ever owned, hands-down. But CarPlay is convenient enough that I likely wouldn't buy another Tesla unless it supported it.