It actually works. Had it hooked up and listening to music in my noisy Kia, and I received a phone call. I pressed the in-line switch and we started talking. He heard me fine using the mic built into the car jack. Surprised me that it worked as well as it did. His voice came through the car speakers. Oh, listening to music in the car worked better than with my 810; the 928 has higher native audio out levels; don't have to crank up the car stereo as much.