The Dealer will put the same 2 piece plugs back in. There is not a 1 piece replacement from the dealer for the 2 piece plug. How they address it is by coating the lower sheath, till about a 1/4" away from the igniter of the plug (not the Threads) with nickel anti-sieze to prevent carbon build up.
I have a 08 Mustang w/ the same plugs. I pulled them as per the SB and coated them as preventitive Mx. Stang only has 2000 miles so they came out real easy.