Tax credits are available to buyers of hybrid gasoline-electric, diesel, battery-electric, alternative fuel, and fuel cell vehicles. The tax credit amount is based on a formula determined by vehicle weight, technology, and fuel economy compared to base year models. These credits are available for vehicles placed in service starting January 1, 2006. For hybrid and diesel vehicles made by each manufacturer, the credit will be phased out over 15 months starting after that manufacturer has sold 60,000 eligible vehicles. For vehicles made by manufacturers that have not reached the end of the phase-out, the credits will end for vehicles placed in service after December 31, 2010.

For diesel tax credits, check the Tier 2, bin 5 requirements. That eliminates all CRD Liberty's produced in 05 through 06 as they were Tier 2, bin 9 or 10 iirc. For that matter, it eliminated every diesel vehicle for sale in the US through 07. The T2B5 was forced into the legislation courtesy of the Union of Concerned Scientists, who prefer gasolene electric hybrids over diesels and lobbied violently against diesels getting any tax credit. Allen Schafer had an article on the entire diesel tax credit debacle - it was a non denial, denial. Yes a diesel tax credit existed - but the emissions requirements were so harsh that no diesel in the US or elsewhere could ever qualify for it.