I will probably be buying a Pioneer AVX-P7000CD player soon, and adding the GPS system to it. Is there currently a way to mix the MP3 playback and AUX in? This will be necessary if I want to hear the directions from the system while using the empeg. If it's not currently implemented (I'm pretty sure it's not) can it be added to the MK II? (If I remember right, the Mk I wouldn't be capable of this, while the Mk II is).