I got an HCH2 in early 06 (love it!) and didn't qualify for the tax credit when I filed last year. If I qualify this year, can I claim it a year late?

I read through as many forms I could find on irs.gov, but the wording isn't clear that you must claim the credit for the tax year in which you bought the vehicle.

Many tax breaks are given a "carryover" and I'm wondering if this is also?

Thanks for any references to clarify.