OK, I guess I'm writing way too much about cars these days, but having had the Bolt for over a year. Here's a summary of the peculiarities. Almost all of these are because the following systems are completely separate and do not talk with each other. It's a consequence of the automotive tradition of "systems integration," that is buy the backup camera from one vendor, the ignition control from another etc.

A List of Peculiarities

This is in order of what happens when you get into the car and drive it around and then leave it.
Setting up the car requires three different pairings. First, you need to create a MyChevrolet login and then connect that you to the VIN of your Bolt. The dealer has to do this properly for you and there is no concept of multiple drivers, so everyone has to share the same login.
Then you have to setup the Bluetooth pairing for the entertainment system, this will get you to the infotainment system. There is a completely separate login for something called Keypass, this is done in the MyChevrolet application and a separate location on the infotainment system that is not related to Bluetooth pairing.
You should also enable the automatic door unlock in the car user interface and "they are stealing your power cable" alarm as well. And also the automatic door locking
When you get close to the car if you have enabled KeyPass, then the doors will unlock, but when you get into the car, if the key fob is not close to the ignition system, it will register, "No Key Available", even though the car unlocked for you. This is because the ignition Bluetooth system is completely separate from the car unlock system which looks for the key fob or your phone if you did Keypass.
If this happens, then you have to take apart the center compartment and reset the ignition system by taking your key fob and putting it on the driver side front of the compartment. There is a little spot there where you resync the key fob to your car.
Now you are ready to drive and the entertainment system and everything is lit up. But when you shift into reverse, it says, "the car is not started". You need to remember to explicitly push the Blue Button underneath to start the car, before you shift. I've done this about a billion times because the lights coming on are the usual indication that the car is alive. Also, the difference between being in "accessory" mode and "running" mode are in the button push, there is no indication where you are. So you have to push the button, then hit reverse and see what mode you are in. I normally hit the button between 1 and 5 times because there is enough lag in the system it is not clear what state it is in.
When you start your car, the car remember the volume, but if you were using say CarPlay and haven't plugged in your phone it will just pick the last FM radio station you tuned in. I can't find anyway to defeat this, so be prepared to be blasted by static your crappy commercials that seem like 90% of what is on FM these days.
When you do plug in your phone, you will not immediately go into navigation or where you last were in the car, you will instead be put into whatever audio you were listening to on your phone. The car does not remember the last audio book or whatever. Also, if you get lost in the interface, the hard "Home" button is your friend, all the Apple CarPlay menus are buried and you cannot (except for the Energy soft button and heating controls get to anything in the base interface).
Now when you start driving, the car will complain "You are not in Park, I cannot update unless I'm in park, I also cannot see the name of SSID of your car", this notice comes up even though you are already in drive and you do not have Wifi service in the car enabled. The update software is running in the head unit and has no idea about the state of the car, when you hit OK, this notice goes away and you have to go down four levels into the settings to find the update dialog.
As you are driving, the head unit will (about once a month) crash. The screen will be completely blank and then it will return. There is no warning about this and if does happen, then you will lose all your heating controls as they are soft keys.
Now when you start slowly, you will have nice 360 camera view that takes over, but if you need it later, make sure to hit the HOME button outside of CarPlay to get it started again. The user interface is quite jarring because CarPlay (or Android Auto) doesn't look like the Chevrolet interface.
When you want to play the music, if you didn't insert the USB in far enough, you can easily get into a mode where the phone is double connected. It has a connection via Bluetooth and also the CarPlay connection. In fact in the regular audio system, you can actually select "Bluetooth" phone and play that while there is a different interface for this in CarPlay. So make sure you are in the right mode when you listen to music.
Now when you get out of your car, the car will sense that the key fob has left and lock the car with a double chime, however the ignition system is not tied to your key fob, so it is easy to accidentally leave your car on. You will get a double chime if the key fob is left in, but it doesn't know how to turn itself off when you leave.
By the same token, if you get out of the car, you will lock any passengers into the car so be careful about just getting out.

Why they are Happening???

One of the big problems with having new devices like a fob and a phone when you connect to multiple independent systems is the network of failures increases, for the Bolt to work, you have to have all the connections working otherwise you get out of sync.
This is one advantage of having a single system (but it would require all the software be written and running on the same platform), so that there is just one place that you can create a Bluetooth connection (not Keypass and Infotainment) and one place where starting happens (so the infotainment and drive system can simultaneously start or stop)
Because the key fob is used by two entirely different systems. The ignition system is not tied to the car lock/unlock system. So when you get out, you need to remember that, make sure that you turn. That is why you can get into the car and yet the car will not start.
Also, the navigation from CarPlay is not integrated into the user interface for the rest of it, so you are in completely different worlds when you are trying to tune the radio vs playing car music.
Then the connection between the boot up of the infotainment system and the start of the car systems are handled completely differently, so when you get in, the infotainment system flashes a bunch of lights as the does the dash, but the car "ignition" system is not on.