This app was mentioned in 9 comments, with an average of 1.89 upvotes
Keep in mind your vehicle probably only supports the headset profile if you can't get the streaming working, so audio quality will be decreased (for example if I recall HFP only supports mono audio, so your solution will have to downmix to that, playing the same audio from every speaker. A2DP doesn't have that limitation). If you're okay with that you'll need to find an audio player that'll broadcast using HFP, or something that'll route sound to it. First one I found is called BTMono, but I haven't tried it and it hasn't been updated in several years. A better bet would likely be an AUX Bluetooth receiver or an FM transmitter
Try BTMono: https://play.google.com/store/apps/details?id=com.bedoig.BTmono&hl=en_GB
It will stream media audio through BT voice, not great quality but it works - I had to use it for a bit with my old '07 Fiesta
I have one vehicle that allows both music and hands free and one that doesn't. I'm going to try this https://play.google.com/store/apps/details?id=com.bedoig.BTmono&hl=en this evening to see if it works in the one that doesn't. It's mine understanding your vehicle has to have essential 2 different BT radios for a2dp and hands free to work .
This is what I told you
"Also, you can use this other app "BTmono" https://play.google.com/store/apps/details?id=com.bedoig.BTmono&hl=es_419 . This way you are not going to have any latency, but the audio quality is horrible."
Is what you call "calling mode". And is that you are expecting from the "gaming mode". The quality is so bad. Maybe for gaining it's ok, but for watching videos no.
Spotify won't appear in the cars menu. If it would work the car would just stream any content from the phone to the audio system as soon you push the media button. Then you will find the phone under "external devices" --> Bluetooth.
Ever tried BTmono? Better to listen in Mono than nothing. https://play.google.com/store/apps/details?id=com.bedoig.BTmono
To the sound of walking on a wired or Bluetooth headset, not on TV, you can use the app BTmono or analogs.
link to a free version BTmono: https://play.google.com/store/apps/details?id=com.bedoig.BTmono link to the paid version BTmono: https://play.google.com/store/apps/details?id=com.bedoig.BTmono_Donate
https://play.google.com/store/apps/details?id=com.bedoig.BTmono&hl=en
Could try that. probably easier to buy a pair of cheap bluetooth headphones though.
If it's possible, it might only be possible on Android. I haven't personally tried these apps but maybe one of these will work for you. https://play.google.com/store/apps/details?id=com.bedoig.BTmono
The way I operate is I have an iPod touch that plays the music. If I want to use Spotify I turn my phone into a wifi hotspot and run the iPod off that.