I got some information on the Crossfire key fobs from a locksmith database on cars. I copied what they had to say into PDF format. I've added this document to the first post in this thread.

The significant thing is that this "print out" seems to indicate that a dealer CAN reprogram the transponder in a key to work with your car. So, those ebay fobs might not be such a waste of money. We just need to find a dealer that knows how to do it, and is willing to do it without breaking the bank.