Considering CarPlay getwired.com

Speaking of CarPlay, Wes Miller has a question (sic):

It is yet another Apple walled garden (like Apple TV, or iOS as a whole). Apple controls the UI of CarPlay, how it works, and what apps and content are or are not available. Just like Apple TV is at present. The fact that it is not an open platform or open spec also bothers some.

I’m not really bothered by the lack of an open spec, but the extent of third party support is a giant question mark right now. It appears that the auto manufacturer gets an app for various car controls, if they so choose, and a few select third parties also have support.

But are these simply built for another target platform — that is, an iPhone, iPad, and CarPlay universal app — or are they separate apps? Is the development process like that for the Apple TV, where Apple provides a comprehensive framework and it’s simply “skinned” by the third party, or is it a blank slate? Hopefully some internet sleuths can answer all the questions I, and others, have about this.