Thanks!
These are not of the floor mat in question, which I believe got messed up while I was working on the car, like the trunk liner, which seems a little warped.
These are samples of how the car was when I got it back:
I do not know what she had on the plastic, but I scraped off a portion:
I really like cleaning with water, just because it cannot leave a residue. When I pulled the floor mats, the carpet looked clean, but was sticky, so I grabbed my citrus cleaner. It said to use a rag and then clean with soap and water. I have scrubbed the mats with plain water, dish soap, and citrus cleaner. I am currently trying two parts hydrogen peroxide and one part blue Dawn. I found some lady's blog. She showed a picture of her floor mats and said that it was embarrassing that she allowed them to get that dirty, even with four kids.
I thought mine looked worse and it probably took those four kids longer.
The lady said that once you sprayed the cleaner on it, run them through the washing machine. I have not tried that part yet.
Thanks for your feedback and good luck with your projects! I always look forward to your updates!