2005 gmc yukon denali r.a.p wire?

Just added a pac aai-GM12 Aux interface. This car didnt have the remote turn on wire in B3, so i was forced to use a 12V switched wire. The problem with this is when you take the key out of the ignition the radio stays on, but the pac shuts off and creates static. This is a very big annoyance. Does anyone know where i can grab a RAP wire from so i can power this PAC GM12 interface?

after doing some research, and going through diagrams. I found a "Rap Supply Voltage wire" which is a Dark Blue wire at the BCM @ position B3 in Connector 2, a 24 pin gray plug. This will only be used as a remote turn on lead for the pac aai-Gm12 interface. I am debating on whether or not to wire up a relay to trigger this RAP wire. I feel like the relay will draw more current than the actual remote turn on of this interface. What do you guys think ?

The relay will draw more than the pac device.