Why's my Chrysler 300 carplay not working?

Sometimes the CarPlay on the Chrysler 300 can juSTStop working, usually because of the general flakiness of mobile devices and bluetooth. So, the best thing to do in this case is going to be to remove Your mobile, turn off bluetooth on the Chrysler, cycle the engine, and re-set everything up. Specifically, on Your mobile (instructions for an iPhone), You'll want to go to Settings, General, CarPlay and then select "Forget This Car", and You'll want to use the in-dash infotainment unit on the 300 to forget the phone. If You try re-pairing the devices, and they still don't work, it's possible there's an issue with the head unit itself that's going to require dealership inspection to sort out.