A hot water extractor will work best on that ground in dirt (floor/seats). And as was mentioned, it's not likely to clean up 100%. It looks like the previous owner didn't rank cleanliness very high on their list. The headliner looks like a smokers car. It will be your toughest challenge because you can't attack it as you would the carpet or seating areas. A microfiber towel sprayed with an all purpose cleaner and carefully wiping is your best bet.