How to keep iPhone from overriding car stereo?

Since updating my iPhone to iOS 16.1.1, both my cars think my phone should be constantly connected via Bluetooth, thus preventing me from playing the radio while driving.

Obviously, I’d like to still be able to make and receive calls like I used to, so disabling Bluetooth while driving is not an option. How do I get it to act like it did before, where Bluetooth only kicked in if I got a phone call or if I was using google maps on my phone for directions in the car?

The same behavior is happening in my 2011 Toyota and my 2015 Mercedes.