Mine gets VERY hot (iphone 12 mini) if it's both plugged into
carplay AND charging wirelessly at the same time. To the point that it once stopped working and displayed "the phone is too <damn> hot".
If either of the 2 functions is turned off, the phone will only get warm.
In its defence, I keep both Waze running in the background and personal hotspot ON for the car's navigation to have access to live traffic. And it is using 5G. I did expect that the phone would automatically stop using the wireless charging when it's plugged into the USB but it doesn't seem to be the case. A physical button for the wireless charging would be amazing. However, since I need to put the car in P to change the setting I mostly keep it OFF.
*The old iphone XS was the same.