Any Bluetooth adapters in place of CD changer
That will allow you to connect any AUX device with RCA output connections (or a 1/8" headphone jack adapted to RCA with an adapter cable.)
I don't know much about Bluetooth retrofit devices, but if any have RCA or 1/8" output, then you can use the GM9-AUX to send the sound through the car's speakers, but you'll still have to use the microphone of the retrofit device.





