My understanding is that "leather trim" is standard on all Stingers. That "trim" means the main
seat bottoms and backs; that synthetic is for the rest; and that nappa is for the GT2 only (US trims, here). So what is wearing on the
seat bolsters is not leather, it is the synthetic. I don't know if the synthetic on the napps is softer than that used on all the other trims; but I suspect that it is, in order for the feel to match the softer feel of the nappa. It would be unsatisfying to have a soft nappa
seat bottom and back, joined to a stiffer synthetic.