With this being a very new car are you really sure you want to tackle this job? It is very easy to destroy the output IC in a lot of these newer decks. If that does happen and you are lucky enough to live somewhere that has a repair shop that will even attempt to repair the unit, it could cost you 200 dollars to get it repaired. A part will have to be ordered, probably coming from Hong Kong and taking a couple weeks to get here. All this time she is not happy with you. So if you still want to do this for her, you will need to purchase 2 Line Out Converters at 20 bucks each, an amp wiring kit probably about 40 bucks and some additional speaker wire. And an additional RCA cable long enough to reach from behind the radio to the amp mounting location. Remove the radio and locate the speaker wires. I should remember to post the info at the end of this post. You will have to cut those speaker wires from the harness going into the deck, cut them far enough away from the plug so you can connect a wire to each end of the cut wire. Connect the LOC to the wires that come from the radio. You then need to get 4 lengths of speaker wire long enough to go from the back of the radio to the location you plan to mount the amplifier. Connect the 4 wires to the wires that you have remaining. Run those along with a remote wire and the 2 RCA cables that you purchased to the location of the amp. Make sure you do not run the wires through the steering linkage, behind the accelerator pedal or the brake pedal, remove panels and hide the wires under the carpet, being careful not to drive any screws through any of the wires you just put behind the panels. You will also need to run the power wire from the battery location to the amp location. You should be able to find a grommet or a rubber boot under the hood that you can get the wire through. If you can't find a suitable location DO NOT run it through the fender and inside the door. She will be laughed at and you do not want that. Put the fuse holder that the kit supplied you with AT the battery. Don't put the fuse in untill the job is complete. Now that all of the wires are at the amp you can connect them. Connect the ground terminal first. Then power and remote. In order to figure out which speaker wire is for which speaker, strip the ends of the wire and touch the wires to a 9 volt battery. Positive wire to positive battery post. Neg to neg this will make the speaker at the other end make a pop everytime you touch the wires to it. You should be able to hear which speaker it is. Connect it to the appropriate channel of the amp. The remote wire still needs to be connected to the radio. Try the power antenna wire of the radio first. If the radio plays but the CD does not, you will have to connect it to the accessory or switched wire of the radio.
Are you sure you don't want to talk her into just adding a sub and sub amp?
Battery RED (+) RADIO HARNESS
Accesory GREEN (+) RADIO HARNESS
Ground BLACK (-) RADIO HARNESS
Illumination YELLOW (+) RADIO HARNESS
Dimmer BLACK/ ORANGE (-) RADIO HARNESS
Power Antenna PINK (+) RADIO HARNESS
LF Speaker (+) BROWN
LF Speaker (-) WHITE
RF Speaker (+) BLACK
RF Speaker (-) YELLOW
LR Speaker (+) RED
LR Speaker (-) BLUE
RR Speaker (+) GREEN
RR Speaker (-) ORANGE