The combox install did come with a replacement USB connection, where the aux plug is now a video in, instead of audio in. My GT already had a USB connection there however, which I just plugged in to the back of it that new connector, if yours doesn't have it, you would probably need to run the cable from there back to the combox. If you contact Patryk with your VIN, I'm sure he can lookup exactly what you will need for your install.
For the combox install in my case, my car had the TCU behind the rear seat, as opposed to the left rear next to the MULF. You'll end up opening up a lot of the trunk (left side floor and center floor), but it's not very difficult. Patryk provides a plug & play connector, so you basically unplug and unbolt the old TCU and then bolt in the combox and plug it in. My USB connection actually ran to the back left of the car, so I had to pull it out of that wire bundle and run it up to where the combox mounted, if your combox will go in the left rear (I think if you don't have the upgraded audio with the big amp, your TCU would be in the left rear), then you wouldn't need to do that step. You'll also need to unplug the MULF, and plug in a fiberoptic terminator loop that Patryk supplies. The last part is to run the video wires from the AV-In connector (USB & 1/8" jack) through the center console and up into the CIC and pin it into the connector... this part was pretty easy also. After that it's just a matter of the remote coding.
Also, I see that you are in San Jose, CA ... I think I recall seeing somewhere that Patryk had someone in the bay area he worked with that could probably do the install for you if you didn't want to tackle it yourself.