The side "bolster" on the bottom seat pad was crushed when I bought the car about 6 years ago, but otherwise it was comfortable enough for driving...until the last couple months. It felt like I was bottoming out on the springs, so...
I had ordered a factory replacement foam seat pad a couple years ago thinking I would eventually get around to it, and the seat finally told me when...lol
I'm enclosing before and after photos, and you can see the difference in the side bolster, but the bottom was where I really felt the difference in pads. It's night and day different.
It's back in the car, and the seat is comfortable again. This was definitely worth the effort.