Maestro Rr and Rr2 stereo interface does, and I'd guess to provide whatever iDatalink-compatible headunit with additional info for gauges, etc. I'm not running one, so don't know more than that, but I'm waiting on the Rr2 to come back in stock so that I can use its three programmable outputs with my steering wheel controls and front lighting.What make/model of 'stereo' connects to the OBD interface, and why?