With or without CarPlay I am not going to be buying a new car anytime soon since I have a recently new car but CarPlay would not make a difference to me.
Not even thinking of buying at this time, but if I was and it happened to be in a vehicle I was interested in then yes. But isn't in anyway a main facture in why I would choose a vehicle.
I just bought a new car and was hoping it would support CarPlay but no dice. Apple's website shows manufactures that support CarPlay but not Models. Most of the car dealerships websites don't say whether/which cars support it either.