bluetooth stereo

I have finally learned and accepted that what I wanted to do will not work because the stereo just receives bluetooth and does not transmit. Thanks.

Car stereos BT typically for music are one way, receive only, will not transmit to BT speakers or headphones. Designed to play your music from the phone or answer phone calls but not really designed to connect to BT speakers.

There are however BT transmitter modules that you can add onto most stereos which allow BT speakers to connect. You may need to get creative to make the connection some stereos may not have line level outputs and you might need to adapt the speaker level to line level..

BT transmitter search

Depends on the radio I suspect.
Bluetooth has three types of modules
If you have a set of bluetooth headphones (Some cars support them) then the headphone has a RECEIVE ONLY (R/O) module
Your phone, your computers have Receive/transmit (2-way) modules
They also make Transmit only modules. (I have one).

Yoru radio may be R/O or it may be 2-way. Depends on the radio.