There are many things available in market for carpet cleaning but I suggest you do not need to use anything just use only the home detergent with some hot water. and remember don't use brush on seat covers.
then what is the problem if you have an efficient way to put a firm check upon the dirt and dust to come out and spread form here and there .. as there are various means are well available to clean it properly .. just place it at an apt spot
I normally used soda for this job but I noticed that it causes harm on my carpets so I decided to use a machine instead of it. you can get reviews on top carpet cleaner machine from www.bestcarpetcleanerforpets.com