I just got the d2/ipod cd-ib100ii/and the xm nav traffic(gex-p10xmt) I also got the pac roem so I could keep my bose system sounding good. My question is all these items have to be grounded. In the supplied nissan wire harness there is a black wire that is used for ground. Can I ground ALL of the parts ( ipod, xm, bipass hack, and the avic ) to the BLACK wire provided by the harness? Or do I have to ground all these black wires to a metal part of my car.