Bit of a Streisand effect going on here...
I had also been messaged about my post in this thread. I asked for clarification and to explain what was wrong with my post but instead they offered to bribe me with "a little gift" in exchange for me deleting my post. This, in addition to the AI slop...
Personally, I'd wire in a new 12V outlet running off an aux switch instead of splicing into the factory harness wiring. Then you'd have both plug options available and can easily undo it if needed.
Version 1.1: Rerouted the positive wire over to connect to a sub-module I built with a fuse block mounted. This fills out the rest of the space in that tray nicely and allows the safe connection of several terminals.
My thought with these is, if you're adding storage space on top of your spare tire, your cargo area is already going to be pretty packed. It's a tradeoff for sure, but I know when we go out on trips, I can't see anything through by rear window anyways.