I found a tear (cloth seats) between the 70/30 seats in the back of my supercrew 6 months after I bought my truck, it was somewhere any normal person wouldn't see, but Ford said they wouldn't fix it because I waited too long. At least I can't see it unless the 30 seatbottom is up. I need leather covers anyway.

 

Well I used a bottle of Simple Green, (yes I know its degreaser) and a bissel carpet cleaner. I had to literally soak the seats with the degreaser, then go over it with the bissel, still I had stains most went away but not all of them. I ended up spilling a bottle of dasani water on it and driving down a dusty driveway and bam there was a new stain. Ebay here I come.

 

I have an 04 and have been fighting this battle constantly. The type of cleaner/ detergent would depend on what the stain is from. Most mentioned here work pretty well. I found the most important thing is a good rinse. When I'm done with the cleaner I soak the area (always do a whole panel on the seat) with plain water and shop vac it out and repeat until the water vacuumed up isn't soapy. This seems to work pretty well and if you vacuum enough it drys quickly.