Well, my son also has a car without Bluetooth and he had an aux cord that he left in his car with a lightning adapter attached. He even found it much more convenient to just turn on his car and it paired to the Bluetooth adapter above. A $10 adapter that just stays attached to the cord you would need for your car anyway if you don’t have Bluetooth doesn’t seem that inconvenient.

However, a wireless cigarette lighter adapter that supports Bluetooth is much more convenient either way.

For me personally, Bluetooth headphones in general and AirPods Pro in particular are much more convenient - especially going back and forth between my cellular watch when I am jogging or in the gym (pre-Covid),my phone, my iPad, my laptop, and my AppleTV. Besides cords get tangled, yanked out, caught on things, etc.