CarPlay is an Apple specific integration with automobiles. It allows you to perform Apple iPhone functionality including iPhone apps through your car. While many cars offer Apple integration, this integration is not necessarily Apple CarPlay, but a more general phone integration with the car. CarPlay is specifically integration with your iPhone's following models: iPhone 7 / 7 Plus, iPhone 6s / 6s Plus, iPhone 6 / 6 Plus, iPhone SE, iPhone 5s, iPhone 5c, iPhone 5. Functions include, but are not limited to Siri integration, iPhone Map integration, iMessage integration, Music/Podcast/Audiobook integration, and integration with apps such as Pandora, iHeartRadio, NPR One and more! Most of the major car manufacturers offer Carplay in their more recent models. Unfortunately, it is not something that can be currently integrated into an existing car sound system that doesn't already have it unless perhaps you buy a new replacement sound system. For more information on Apple CarPlay read here.
I love technology and how it enhances our lives! Just think, without the Apollo moon missions, we might not have calculators! Imagine!!