Are you looking to replace it or fix it? If I had the $, I would get a different fabric for that part of the seat, the one thing I dont like about my MS3.
I'd fix your friends while your at it. I personally don't smoke and have pulled over and kicked my friends out in snow while they enjoy a drag while I wait inside my car for them to finish. But honestly, if he/she hasn't already, that person should offer to help fix it. YOU'RE not the one that burned your new car.
Alexi