Hey Brad, there isn't one really. The old CCC systems that came with the snap in adapters didn't really support it, the newer CIC systems do. I am not sure if a firmware upgrade to the CCC system will enable this feature, or if you'd need to upgrade the Bluetooth module to a newer revision. The snap in adapters also only supported older phones, so if you have a newer generation iPhone, Samsung, Blackberry etc it wouldn't work. The other option is an aftermarket Bluetooth, like Parrot, that would probably give you the required functionality. I eventually gave up.