For full carpet I recommend DP total interior cleaner.
Before
After
The center console was not cleaned yet. As you can see it got the majority of the stuff out. It probably would of gotten more out with another pass with the PC carpet brush. It does a GREAT job on light to moderate stains, but for VERY heavy stains you might need something with a little more power. But the DP cleaner is the only carpet stuff Ive used that doesnt require a rinse, and doesnt dry leaving the carpet with a sticky soapy feeling. It smells really good too!
BTW, this is a 93 Lexus. As you can see the stains are under the seat. So that has probably been there for YEARS.