The way it works is you plug in your iDevice, preferably an iPhone, to a socket within the vehicle’s dashboard using a USB to lightning connector. You then get a nice heads-up display (HUD) with various options at your disposal such as the ability to play music or enter navigation mode.
Navigation consists of Apple’s Maps app and is really the bread and butter and main reason you will be using CarPlay. Surprisingly, the map followed the vehicle almost to the exact dot in real-world terms as it was very accurate over a 4G LTE connection. It would also briefly work after a connection interrupted and if it came back on — say you were driving through mountains and came back to the main roadway — it would resume operations quite smoothly.
I would definitely recommend it over just using an iPhone with a standalone mount and having Apple or Google Maps on the whole time. There is less fiddling involved and the fact it is plugged into the dashboard means the battery stays charged. The actual experience seems even more accurate with the map tracking, although this could vary case-by-case (depending on hardware you are using and your LTE connection).
When the vehicle is parked, there is also a nice navigation showing its parking from the rear in terms of how close it is to other vehicles or hazards. This is nice when you want to back out of parking and get back on the road and can help out in parallel parking or other driving-related endeavors.
The music can easily play in the background although this takes some fiddling away from the navigator and should be done by another person in the car in order to prevent unsavory roadside conditions. I do not recall exactly if the vehicle we rented had a speaker system connected to CarPlay or anything worth bragging about in terms of speakers. However, I think and this is just me reminiscing, it played from speakers outside the phone (again this could be just me reminiscing as I would have to research this further to make sure). The potential is there, however, if you have a great audio system in your car to have it connected through CarPlay. Of course, you can also always bring external speakers connected via Bluetooth to a regular iPhone not connected to CarPlay anyway, but I recall that the sound output was quite nice.
I was not able to try the other apps or options like Podcasts or Audiobooks, but can see how these apps can make a long drive much more pleasant. the sound should be playing in the background while the navigator is turned on, thus once a song is selected, you should not have to go back to the separate apps. However, again, I was not able to try these apps.
The bottom line is I see a lot of potential in concepts such as Smart Car and adding connectivity between mobile devices and vehicular systems. I see potential in not just navigation and sound, but also with connecting to the maintenance and warning system of vehicles. This way, maybe more accurate readings of maintenance warnings could be checked (even though vehicles already have such warnings in place it could aid it and make it easier to follow by the driver). I also see potential with external apps, lighting systems within vehicles and more.
During my time with CarPlay I either did not notice or there was no Siri integration and this is a huge potential as well. It is a good idea for such a navigation system to allow drivers to focus their attention and eyes on the road and using voice for commands between the Music app and Apple maps would be a huge factor in making this system make sense and be safe to use.
My one gripe was to switch radio or music tracks one had to click on the Music app icon (sometimes not even showing on the main navigator sidebar) and go back to the main app menu exit the navigator or Maps app. It would have been nice to have a more of the various app icons showing directly with a pull-down menu of sorts on the navigator for this purpose (switching around apps and menus). However it is also possible I was using an older or outdated version of CarPlay.
Vehicles are getting smarter today with greater navigation systems and more automation such as greater warnings near tight parking spots or automatic readjustments by the vehicles themselves. With driverless cars getting closer to reality, systems such as Apple CarPlay are the middle ground or transition to fully automated and AI-driven vehicles.
I know Google has Android Auto as its answer to CarPlay and I look forward to seeing it in action in the future when I get a chance as well.