You can get a BT transmitter/receiver that hooks up through an audio cable. I've got a Taotronics that I purchased on Amazon for about $30. Charges via micro USB and connects via 3.5 audio jack. While it will not connect to my Ford or Subaru systems, it will connect to my Cardo, Bose and other systems with ease.
I use it to connect my XM Pioneer Inno radio to the Bose BT quite often. All you need on the radio is an audio out jack with the correct cable adapters.