I would like to purchase a new unused key, but the mercedes key and not the standard crossfire key... something like...

http://cgi.ebay.com/ebaymotors/NEW-U...98546207QQrdZ1

Will I be able to program it to work on the crossfire?? Will I be able to order a blade or possibly switch blades with my old worn out key?

 

It would have to be a MB SLK key, I would imagine.

 

Yes you can program it, just follow the manual. No need to have a new key cut, just push out the retaining pin in the Chrysler key and reinstall it in your new Mercedes fob.