On the '18, the schematic shows fuse #2 supplying cargo area outlet as well as center console outlet.Glad to hear you found the mistake without burning up a wire. Someday I would like to get around to doing this myself, but I haven't prioritized it yet. But, I'm more interested in making the outlet in the cargo area constantly hot. Does that outlet share the same circuit as the console/cubby outlets? (i.e. if I copy your mod, will it power the rear outlet as well?)
Fuse #7 supplies the front outlet.
Both fuses are fed from ignition controlled relay "Accessory Relay 2".
So you would need 3 add-a-taps: 1 to take power from an always-on donor circuit, and that feeds the other two taps in place of fuses 2 & 7.
As noted earlier YOU HAVE TO KNOW WHICH SIDE IS THE LOAD SIDE OF EACH FUSE vs. the HOT/SUPPLY SIDE.