Here is the IRS page about how (and how much) credit to claim.

http://www.irs.gov/newsroom/article/...157557,00.html

Relevant part:

Form 8910, Alternative Motor Vehicle Credit, is used to claim the qualified hybrid vehicle credit as well as for vehicles qualifying for other provisions of the alternative motor vehicle credit.

If the qualifying hybrid vehicle is purchased for business use, the credit for the business use of a qualifying hybrid vehicle is reported on Form 3800, General Business Credit.

For qualifying hybrid vehicles acquired for personal use, the credit is reported on the appropriate line of the taxpayer’s Form 1040, U.S. Individual Income Tax Return.

For additional information on the proper reporting of the alternative motor vehicle credit, see the instructions to Form 8910 on page two of the form.

The new qualified hybrid motor vehicle credit begins to phase out in the second calendar quarter after the calendar quarter in which at least 60,000 of the manufacturer’s qualifying passenger automobiles and light trucks have been sold. Additional announcements are anticipated regarding the phase-out dates for all of a manufacturer’s qualified vehicles and will be posted to this site.