Shane,
Great thread! And you got a free joint out of all your work

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Can't wait to hear more about the seat heater replacements. Mine just seem weak and take a fair amount of time to get warm. Apart of your seat heat panel is it just for the bottom seat portion or will you have a lower lumbar panel too?
I know it wasn't on your list but if you think you'll need/want an aux circuit for the rear of the LC (think fridge/freeze, charging circuit for a 7-pin trailer plug, etc.) now would be the most opportune time to at least route the hot wire to the rear panel.