sounds like you have just been a bit namby pamby in your attempts and not given it some propper elbow grease.
Steam cleaner.
Fire. Fire fixes everything.
/pyro
Disclaimer: This may destroy you, your car, and anything nearby.
Hot water on a tea towel and leave it for aslong as its hot then scrub off with more hot water
I heard handing the car into the dry cleaners also works.