Saggging front passenger seat?

I've noticed that the front pass. seat has not retained the rolled and pleated form in the middle of the seat. It has been this way since new. No, it's not because of heavy weights in the seat. The only one that sits there is my wife who weighs 110 lbs.

In comparison, I weigh about 240 lbs. and the drivers seat still retains it's origininal shape. Of course the drivers seat is always in use as opposed to the pass. seat that may or may not be occupied.

If you run your hand over the leather, it almost feels like the cushion is sagging.

Is this because of the air bag sensor?

How is everyone elses' pass. seat holding up?

I have an appt. with the dealer on Monday, and wonder if I should bring this up.