As to whether people choose a vehicle for CarPlay - people are thinking of this the wrong way. Someone isn't going to drop $30K on a certain car only because it has CarPlay. That would be kind of ridiculous. People often shop for different vehicles in the same class (the classic Honda Accord vs Toyota Camry is a good example). In this case, when two vehicles are similar then a feature as simple as CarPlay can be a deciding factor in picking one vehicle over another. At least until such time as every car supports it.
Agreed, I just change my car a few weeks ago, within the budget I had, pretty much everything was a similar size/performance MPG etc, so it was the 'toys' that made the final decision for me.