I am working on installing a car pc into my 2006 pontiac G6. The problem that i have is the there is a DIC in my car, that if i take out i lose thing like door chimms and such. For the 06 G6 there is a metra dash kit that keeps the DIC and lets you install an aftermarket radio. Below is the Wiring code for this dash kit:

METRA / EIA WIRING CODE

12V Ignition / Acc . . . Red
12V Batt / Memory . . Yellow
Ground . . . . . . . . . . . Black
Amp Turn-On . . . . . . Blue / White
Right Front (+) . . . . . Gray
Right Front (-). . . . . . Gray / Black
Left Front (+) . . . . . . White
Left Front (-) . . . . . . . White / Black
Right Rear (+). . . . . . Violet
Right Rear (-) . . . . . . Violet / Black
Left Rear (+). . . . . . . Green
Left Rear (-) . . . . . . . Green / Black

2 - Plug the clear 10 way and 12 way connectors into the back 2 of the 99-3303 housing.
3 - Connect the Lt. Blue 24 way connector to the factory 24 way harness.
4 - On vehicles equipped with Onstar, connect the Black 12 way connector to the factory 12 way harness.
5 - Re-connect the negative battery terminal and test the unit for proper operation.
6 - Reassemble dash in reverse order of disassembly.

Obviously i would be able to use the available 12V ignition/Acc to power the car pc. What would i use the 12v Batt/Memory wire for? and i assuming that with the factory wiring for the speaker i would still need to use an amplifier?
If any one has an ideas the could give on the best way to use the wire harness to connect my car pc to my car, it would be greatly appreciated.