I'd try "jungle jake" run through a professional carpet cleaner

http://www.farmandfleet.com/catalog/product.aspx?i=217064&h=020405001

Safe for carpets, and it's one hell of a degreaser. biodegradable, non toxic. I like it. It's by the detergent and other wash stuff.
~Nate

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95 Honda Shadow ACE 1100.
1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)