TL;DR: Best wireless streaming solutions for older car with only bluetooth calling?

Hello. I have a 2008 Infiniti G37s. I do not plan to upgrade anytime soon as I love my car. However, it only supports phone calls over bluetooth. No audio streaming. Unfortunately, the screen where all of my controls are also controls some important settings for my car. So, I can't replace it with an aftermarket stereo.

I'm looking for some kind of adapter I can use that doesn't sound like absolute dog shit. I have only ever seen bluetooth dongles with awful audio quality. I am skeptical to get one. I understand there will always be some loss of quality switching from AUX, but the convenience is more important to me.

Also, I'd like to still be able to use the bluetooth calling at the same time (if possible). It works very well and stops music when I get phone calls. I have seen that I can upgrade my head unit to one of a slightly newer G37, but I haven't been able to confirm it from an Infiniti dealer if it would work.

The Spotify Car Thing was going to be a perfect solution for me, but for some reason it does not have an auxiliary port. IDK why they didn't add one, because I'm sure there are a lot of people who would have used it in my use case.

Let me know what you use for transmitting audio in your car? AUX is king, but there have gotta be some good bluetooth options. Thank you!