Why would carplay be wireless?
To me personally I would rather use it wired as it charges the phone at the same time and gives you much better audio quality.
Apparently I am the minority though. I currently visit a couple car enthusiast sites and there message board. Out of the 100's of people that have replied to the the CarPlay topics, about 90-95% said they will not use it because it is not wireless. This goes for people that have it already and others that don't care for it at all because of the lack wireless interoperability.
I disagree with them completely but apple needs to make wireless CarPlay available if they want it to be successful with the people that have in there autos.
What's the big hold up anyway? Didn't they announce wireless CarPlay with the release of ios9? I know they shot down VW from showing their version of wireless CarPlay early this year but that's all I've heard about it so far.