Well gentlemen, there is no definitive answer on where to splice in the remote wire for an aftermarket amplifier. I got down to it yesterday and based on the wiring diagram sticky... I think I have the answer. On the back of my 2013's oem radio, there is a 10 pin connector which houses the power wires for the HU. You can tell which one it is based on the super thick yellow "ignition" wire that enters here. About 2 pins over, (if i recall correctly) there is a thinner blue wire with a white stripe. This is labeled as being solid blue in the wiring diagram but has a thick white stripe on the wire. This is your 12v source.

I used one of these types of splicing connectors so that no cutting was necessary.

From here, all i had to do was run the RCA's from the back of the HU and do my power wiring. Worked perfectly first time and took less than an hour. These cars are like Legos.

 

I normally wire the remote wire into the radio fuse or something else that turns on or off when the car does. But nice solution! If you have any questions about my methods let me know!

 

I installed my amp a few months ago. There are two wires that you can tap to. If you have a circut tester you can varify this. Ground the alligator clip to support bar behind the glove box, then on the small 10 pin harness it should be blue or yellow. I forget. But when you turn the car on the light will come on. Push the power button and it will go off. I did this, and it worked untill i drove it to work after installing. For some reason it stopped powering my amp. So I decided to go with the radio +12v. Works just the same. Anyways, hope this helps others.

 

From what I can tell, the 12v source gives continuous power whenever the radio is receiving power. If the key is just in the ignition in the off position, or not in the ignition at all, the amp receives no power.