FWIW.. The same area (on the left of the driver's seat) gets quite dirty on mine too. Mine's what is it? Sandy beige or whatever? (perforated)

At first I thought "is this ACTUALLY coming apart already?" but no, it's just dirty. The rest of the seats get good use and they're spotless.

The dealer talked me out of nappa seats - said they don't hold up well and most of their customers are not very happy with them. I kind of had to listen because why would someone who makes a living selling me more and more expensive crap tell me not to buy it? I do also like having my fat butt ventilated. That car gets hot.

And yes, I think people with very light interiors are crazy too.