He has an Android as his avatar and promotes his Google+ page in his signature... I wouldn't hold my breath for sources. In any case, we know they don't exist or Volvo, at least, would be getting sued. They support both Android and CarPlay in their upcoming models.
I'm sure engineering priorities are the reason, as you say. The Media subsystem sucks for everyone, not just Apple users. And indeed, while CarPlay would be neat I suspect most people would be mostly happy with the simple iPod interface provided in basically every other car on the market today. We'll get something when the Media player finally makes Tesla's priority list.
Agreed GizmoToy... My expectations are now so low that I would be happy with the standard old iPod interface (= simple access to playlist...) that I have on my other vehicles from GMC, BMW that are years old... Using my iPod to access and control my music works, it just feels very old and takes the "shine" off of what I thought I might get by paying $2500 extra for a premium sound system. I will read the manual in detail next time before buying from Tesla and not make such brash assumptions lol. -- Cheers.