My guess is a defective seat heater. Let the dealer replace it. And it's possible that the seat cover & cushion need replacing too.
If they won't replace the seat cover & cushion, I would insist that the tech shows me the seat while it's apart to replace the heat pad so I can see for myself that the cushion & cover are not burnt. I wouldn't want a burnt smell in a new car.
If they won't replace the seat cover & cushion, I would insist that the tech shows me the seat while it's apart to replace the heat pad so I can see for myself that the cushion & cover are not burnt. I wouldn't want a burnt smell in a new car.