Ditto on John68's advice. Detergents should be used sparingly. Just enough to allow the fiber in the carpet to "wet out". This is helpful due to most carpets being treated with teflon like chemistry to aid in soil and stain protection. Detergents will leave a residue that will accelerate the soiling after cleaning. The best cleaning systems are hot water extraction with the extraction being the most important part of the process. Spot cleaning with water and a mild detergent is also benificial.
68 convertible, Grotto blue, 327 TH350,3.08 diff