Disclaimer: Proceed at your own risk, as I accept zero responsibility for your attempt to wire your own equipment or any resulting damage that could occur by utilizing the following information.
In short, I found the answer to my wiring question above. For some reason the stock amp wiring discussion is an elusive topic online (there are a few references on this forum with conflicting opinions), though a quick visit to the hyundaitechinfo.com site for a true solution proved to be very informative. Great site by the way... Subscription required.
If you have a 2015 Genesis with the Ultimate Package (Lexicon System), the stock amp is located in the trunk under the the driver's side quarter panel. To access it, you must remove the two Phillips screws and the two bolts on the base of the carpeted trunk cover. This will not remove the cover, but it will allow you enough room to pull the cover outward enough to access the amp.
You'll also want to remove the plastic housing that covers the trunk latch (One additional bolt on the passenger side, then pull straight up to pop the two plastic pins out).
The Amp has three modular connectors going into it, one small plug (2 orange wires), one white and one grey connector. According to the manual, pins 4 and 5 on the lower Grey Connector feed the sub-woofer. Pin 4 (on my car) is a Grey Wire with a Black (Gr/B) line and is the Positive (+) feed. Pin 5 is a Blue Wire with an Orange (L/O) stripe and is the Negative (-) feed. As with any install, test all wires (radio on) with a volt meter to ensure the wire isn't a higher voltage feed.
Describing the unplugged Grey Modular connection, as best as I can:
Holding the modular plug with the open end facing you and the latch you pinch to remove the modular plug at the top, here's the wiring config:
12......11/10 /9 / 8 / 7 / 6 / 5 /4 / 3 / 2........ 1
.........22/21/20/19/18/17/16/15/14/13..........
Note: Slots 1 and 12 are the bigger open slots on the outside of the plug, separate from the internal cluster.
Further, the battery is located in the trunk, next to the spare tire on the passenger side, which makes connecting the amp to the battery a breeze. You must use an in line fuse between the battery and your amp!
You can run your amp's "remote on" wire to the fuse box as others have suggested, though there are also plenty of accessory power wires capable of triggering the "remote on" wire to your amp in the trunk area - Always use your voltmeter to test for a 12v signal, both with your car off and on. I would
strongly advise using a relay to feed the "remote on" feature of your amp.
Using a relay involves a visit to your favorite auto parts store to purchase an automotive relay (ask them, they'll point it out). The relay allows you to feed the "remote on" wire to your amp with power directly from your battery, but only when the car is on. It does this by using the accessory wire that you tap exclusively as a trigger (not a power source). When triggered, the relay sends power to the "remote on" wire of your amp from the battery. This is the
safest way to protect your system, and your auto parts dealer can explain more if you haven't used a relay before. Also search Google, as there are numerous video "How-to's" on the topic.
Link to an auto relay example:
http://www.amazon.com/Absolute-RLS1...TF8&qid=1453559976&sr=8-3&keywords=auto+relay
The above is by no means a full description of the install process, though I hope it closes the loop on the majority of confusing issues many have been researching. Feel free to respond with any clarification needs or questions.
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