Ok, I found out what the problem was. These were hard pieces that were a part of the heated seat. I was able to peel the seat cover off (the hog rings were a treat to work with) and unstick the heated seat and after trimming it, stick it back on further back and get the hard spots in the last crevice in the seat cushion.
So long story short, it was a huge pain but I managed to fix it. I'd still be curious though to hear about anyone else, I find it hard to believe that these only bothered me. I had people ride in the truck with me and once I told them about it, they could feel it but they didn't notice it before I mentioned it.