There is no aftermarket replacement for the QP VI.
There is a 12.1" "Tesla"-style aftermarket navi for the Ghibli, that also replaces the HVAC controls and hijacks the car's setup/controls, and while that is compatible with the QP, it replaces the whole center console, including the air vents. A decent audio shop with the ability to make custom stuff, might be able to gut the display and the internals from the Ghibli unit and manufacture a custom bracket for the QP's dash if you want to go that route.
If you just want Car Play or Android Auto added, that's way simpler - plenty of Chinese stand-alone boxes that piggyback on the car's original infotainment touchscreen.
Shane, do you feel sound is "good enough"? I have a feeling that my sound is a little off. I rented a Chrysler 300, and it sounded wayyyy better than my car. Most cars I have had recently have sounded better and my car has premium sound.