Buy a small Bissel extractor
Spray down with apc and spray the shit outta the seat. Soak that plaid up. Take a brush or a brush attachment for a drill and scrub the ish outta the seat.
Then take a small Bissel extractor and extract all that outta the plaid!
I do this once a year. Keeps the seats looking new after a salty winter.
Good point to bring up. It’s more important that the bristles aren’t too stiff. I think you do more damage sitting in the car or getting in and out of the car everyday especially with jeans!
I would try cleaning them and see if color comes back. Number of things can cause that:I see, my seats look a bit faded but the windows are tinted and I very rarely have passengers so dunno why.