For an energy-efficient vehicle tax credit 

• Click on Federal Taxes (Personal using Home & Business)
• Click on Deductions and Credits
• Click on I'll choose what I work on
• Scroll down to Cars and Other Things You Own
• On Energy-Efficient Vehicles, click the start or update button

Or enter energy efficient vehicle in the Search/Find box located in the upper right of the program screen.  Click on Jump to energy efficient vehicle