Simple Bluetooth device won’t connect

What is your question?

When I try to connect a simple Bluetooth transmitter to work as a “line in” (since there is no aux) it seems to pair, but then it says it’s “not compatible with SYNC” and it doesn’t show up on the list of available devices. All I want is to connect a device that doesn’t have Bluetooth to my cars audio...if there’s a better way to do that, by all means enlighten me. I’ve asked if it’s possible to install an aux cable (the ideal solution) and been given a resounding “no”.