I got grease on my car upholstery years ago. Can't remember what got it off, but it is possible. Have you gone on-line to look up stain removal? You should find a guide that lists methods/products that work. Another suggestion is to call your local car mechanic. He/she will hopefully know how to remove the grease stains. I was worried when it happened to me that my car seat was ruined. The grease came out and everything was ok!
Barb