After I removed the car seats, I vacuumed the seat thoroughly and picked any crusty or sticky substances from the upholstery surface. I then mixed the Dawn, vinegar, and club soda together in my heavy duty spray bottle and shook it lightly to mix.I sprayed liberally over the stained areas and let it sit for about 5-10 minutes. I took my scrub brush and scrubbed in little circles over the stains. To my amazement the stains started to lift and disappear. I ran out of time to finish, but the next morning when I came back most of the stains were completely gone except a few of the worst ones. There were water marks where I sprayed my cleaning solution the day before so this time I used my Hoover SteamVac and only filled it with warm water. I resprayed the stained areas that did not come out and then scrubbed again. I used the hand held spinning attachment and water sprayer, and as I went over each section it sucked up the water. It was amazing how well Dawn, vinegar, and club soda worked together.