Though these are hard to find, I'm sure one will turn up if you keep posting in the "Want to Buy" section of this forum. You may also want to have ebay send you a notice when this item gets listed. This assumes you are registered with Ebay.
I have one of these cars and sent it to another forum member to finish the paint scheme like the prototype. I forget who was doing this but he did a nice job.
Hope you find one soon. All the best,
Paul