> buy one of those tablets that you stick on your dashboard and plug into the aux port
Every single car I have been in in the last 5 years or so has Bluetooth. No need for aux ports in this day and age, especially when devices dont have headphone jacks anymore.
Are you stuck in the 2000's?
I still use headphone jacks on my phone, I wouldn't buy one without it. It is just more garbage to manage and more stuff to fix when it doesn't work. It takes half a second to plug in a cable and I don't gotta run around broadcasting a bluetooth signal which drains battery when not in use and takes as long to disable as pulling out a plug. Plus it is often lower quality than the cord.
Bluetoothing to your car is to me the same energy as using "wireless" charging stands for your phone. You are just replacing a physical tether with a less efficient digital tether of higher complexity for no actual gains.
I thought the same until my latest pixel refused to use the headphone jack to the car because it detected the hands free communications in the steering wheel as a microphone and decided to block audio out with notifications telling me to set up Google Voice Assistant first (get fucked).