Forgot to post this the other day...
If you use salvage 16 way connectors (Furukawa) for the seat you'll likely need to de-pin at least a few terminals as you'll end up with heavy gauge wire for signal pins and light gauge wire for power supply pins.
I could not find any videos on how to de-pin them but I have figured out a way that 60% of the time works every time.
Step 1) Buy some rando cheapie de-pinning tool set from the worlds biggest electronic flea market, Amazon. Make sure it includes at least one style de-pinning tool that looks almost like a big tongue depressor.
Step 2) Get your favorite metal material removal item (heavy grit sandpaper, file, whetstone, whatever) and file down the edges a bit so it'll easily fit in the back of the terminal. Next file down the top so you have a nice thin flat wedge type shape. (Stares at stab wound on thumb) It doesn't need to be super sharp, just thin.
Step 3) Pop open the front of the connector. Now use your thin wedge to try to wedge it between the connector and the mystery plastic tab as shown below. Give the wire a tug. It won't come out. Try again. Try five times. Swear a lot. Try again. If you get it right the terminal and wire should come out rather easily and you shouldn't have to pull hard.
Step 4) (Optional) Reward yourself with a tasty adult beverage.