The federal income tax credit applies to
qualifying hybrids first placed in service on or after 1/1/2006. The question is whether the 2005 FEH qualifies. The 2006 FEH does, but I don't see the 2005 FEH on any of the qualifying lists.
http://www.irs.gov/newsroom/article/...156044,00.html
http://www.fueleconomy.gov/feg/tax_hybrid_new.shtml