Got this response from a large Southern California dealer regarding my pre-production order inquiry for an '06 GT through X-Plan:
We are not participating in the X-plan program on 2006 Mustang GT's. Due to the limited availability of 2005 GT's we anticipate the same for the 2006 model.
UHH OHHH! I hope this isn't indicative of all dealers. If so, there goes my GT!
-goof