Mold is tough, especially on fabric. I think you are going to find that the pad under the carpet got wet and needs to be replaced. Whether the carpet can be salvaged or not is another matter. Also for the seats, the foam under the seat probably got saturated and you really need to get the fabric off and inspect, dry, replace the foam and batting. I just don’t think there is any other way. Again hopefully the fabric can be salvaged. But you have to get the seat out, pull the carpet and go from there. When cars get wet inside, you have to take immediate action to get the pad and seat out and dry right away or you’ll get mold, then its a big problem.
We had to put our pop up camper down in the rain once and it was a week before I could get it opened and dried out. I got mold in the canvas and bed pads. No matter what I tried or did, I could never get it out so I couldn’t smell it. I finally just junked it and our camping days were over. My wife was very grateful for that.