Oil or grease based stain on carpet

[HuskyMan]

I have been cleaning the carpets in both cars. I used the Woolite Rug Stick carpet cleaning kit and have to say for $20 it really cleans the carpets well!

however, I have a couple oil or grease based stains that don't want to come out. I used the Woolite Oxy Deep Stain remover (spray it, let sit then use a towel to "lift" the stain out) several times on these spots. as a result they have lightened up, but are still noticeable. anyone have an idea of what might remove this type of stain from mercedes carpets?

BTW, here's the link for the rug stick info....

http://www.woolitecarpet.com/Products/Product.asp?catalog_name=BISSELL&category_name=FeaturedProducts&product_id=Rug+Stick+Kit