Just as a reminder and to clear some muddiness:

You cannot use the hybrid tax credit in increase your tax cash refund.

It will only allow you to "reduce the amount of tax you owe dollar for dollar" the amount of the tax credit.

For example, if you OWE the IRS $2600 at your final calculation, and you have a $2600 credit for a hybrid car, then you can PAY the IRS the $2600 with that tax credit.

What you CANNOT DO is this: At your final calcuation, the IRS OWES you $400, so then you want to get your $2600 hybrid tax credit applied and get a refund of $3,000 - that will not fly.

So it's still time to adjust your taxes so that you OWE MONEY at the end of the year and can take full advantage of the hybrid car tax credit.

See this page for a good detailed explanation:

http://www.nysscpa.org/sound_advice/money_9.11.06.htm