I Agree with Tom - I had a Jetta that I was overhauling for my daughter and the blue carpet in it was stained with grease and oil and was loaded with sand and grit. I removed the carpet on a hot sunny day and pressure washed it while it was clipped to a vertical board - the dirt and sand that came flying out was amazing. I then treated the grease stains and pressure washed again repeated the process 4 times then shampooed the entire carpet and rinsed with the pressure washer and let hang for 2 hours for the water to drain out then layed it in the sun to dry - the carpet looked like new. The carpet came out a greyish blue color and went back into the car the sky blue it was originally. A lot of work but inexpensive to do.