Apple CarPlay works over my USB-C cable, at least in my 2018 Subaru Crosstrek on an iPhone 15. No Bluetooth required I am fairly certain. I also have to unlock the device every so often with my Face ID -- unsure what triggers this as it is not 100% of the time.
My car also uses wired Android Auto, but somehow after I set it up the day I drove it home, my phone automatically connected to it via Bluetooth. I recall something similar when a friend plugged in their iPhone but I’m not sure.
