I used to clean carpet professionally, and I have a professional dual vacuum carpet extractor I use for carpet and upholstery, and I can tell you from experience that Bissell doesn't make an extractor with strong enough suction to remove enough of the detergent. Also if you put too much detergent into your solution, even if you had a professional extractor you will still have soap residue left in the carpet. After the carpet dries, the soap residue attracts dirt, and dirt sticks to it. If you have spilled liquids and they soaked into the padding, no professional machine will clean it while in the vehicle. You need to remove the carpet from the vehicle and flush out the coffee or whatever until the water comes out clean, then you can clean the carpet. Stains will reappear if you use too much soap, or if the backing or padding has been stained.