Hey guys, I have a D-2 that came with the car and I bought a IP-Bus to RCA, and did a Monster RCA to AUX cord but I don't know how to activate that port.. What to do!? Is there any hacks or bypasses? Thanks 

Just turn Aux on in the menu and then select it as your source. Although, I am curious as to why you used a IPBus RCA instead of the built in input.