Simple Green is quite honestly my all purpose cleaner for the car and for my house.
I use simple green for all the stains on my car mats. Spray on the stain, full strength, lather with your fingers or a soft brush, blot dry with a clean cloth. I've used this for coffee and dog stains,aAnd other unidentifiable stains. Works on stains inside the house as well. Test an area first for colorfastness.
Degreasing the engine of your car. Careful not to spray electrical parts.
There are so many uses its impossible to list them all.