Similar topics have been posted before, but I wanted to refresh the topic for anyone hoping to do some spring cleaning. The washing machine does wonders for floor mats and it means you don't have to scrub your arm off trying to lift out the little bits of sand and dirt. Pre-soaking/rinsing the mats and washing with hot water to keep them flexible has been mentioned as working the best by some other members. People with lighter color floor mats probably know and are frustrated with how hard it is to keep them clean.
Here'* how mine turned out today:
They weren't overly dirty to begin with because I washed them about a month or two ago, but decided to do it again since I had the chance and will be busy until summer basically. I wish I would have started doing this sooner because maybe I could have lessened the staining on the driver'* side. Nonetheless, I like how this works. Mats are still damp in the "after" picture so they should look more improved after dry.