you can probably rip one out of another car or get some rubber like from a craft store and cut it to size. Then hit it with some glue.
That looks better than the stock one!I got a rubber mat and cut it to size. I don't even have it glued down, I just set it right there,and it stays in just fine. Here's a pic: 3-22-10 008 | Flickr - Photo Sharing!
--*Rob