I plan on installing a carpc into my 06 GT.
How easily can I connect a sound boards out connections to the shaker 500 speakers/amps?

 

Fairly.

The main question would be is this replacing the existing head-unit? If yes, then this requires:

1. Usual 24 pin(gives delayed accessory turn on line 12v power, and the 4 speakers)and 8 pin(shaker factory sub wires and turn ons) adapters that you would use to wire a head-unit, easily found from posts in this section. The 8 pin adapter usually gives you RCA inputs(male) to use.
2. A 4 channel (or 2 2 channel) amp that would do the amplification of what the head-unit would normally do, 15-40watts per channel RMS will be fine. This is for the 4 base speakers in your car(front and rears).
3. A stereo 3.5mm phono to RCA adapter for the sound-card's output to adapt to it for both the 4 speaker outs and the mono sub line if the card has it; however, I would use the existing amp's line out to do this, by running another RCA line back to the 8 pin harness's factory sub input. This is how mine is currently done. Cuts down a crapload of alternator noise until the audio driver can be initialized if you do not have a delayed start-up line set up from the mobile PSU to the 5v factory sub amp's turn on(s), or something like an fusion brain, or arduino to do this for you.
4. And of course you will need to give 5v to the factory amp turn on lines. I suggest either using the delayed accessory line with a 1k ohm resistor to do this, or using whatever mobile PSU you plan on to do this, as nearly any of the good ones will have an 5v accessory out line for any odd USB peripherals you might need to power outside of the computer itself. Opus units are IMO the best. Never had any RFI issues with the few I've used, where as others were awful.

Example harness (Part #70-5521) 2 RCA's below as it's made for both shaker 500 and 1000 setups(front and rear subs):

 

cool thanks for info.
yea original HU is going to be replaced by a touch screen.
Gonna try to enlist help of a friend whos done alot of car electronics work