#1: The $7,500 income tax credit is only available against your income tax liability. That is the amount figured on line 44, based upon your taxable income (after itemized deductions) which is on line 43. It is then further limited by any credits appearing on lines 48 through 53. For example, if your income tax liability is $7,525 and you claim a foreign tax credit of $100, then your electric vehicle credit is limited to $7,425, and the unused $75 is gone forever. Moreover, any additional taxes that you might pay (SE tax, nanny tax, net investment income tax, additional Medicare tax on earned income, 10% penalty tax for premature distribution of a qualified plan, etc.) are not affected by this credit. For example, your income tax liability on line 47 is $6,000. Your SE tax is $3,500. The electric vehicle credit will wipe out your $6,000 in income tax, but you must still pay $3,500 in SE tax. Again, the $1,500 of unused credit vaporizes.
#2: The deduction for state sales taxes: The itemized deduction for taxes on Schedule A is the greater of your state income taxes paid or the sales taxes paid based upon your income plus the purchase of the Tesla or any automobile. You do not get both. Look at Schedule A, lines 5a and 5b. See that little word, "or?" And since most of us who purchase these autos are subject to Alternative Minimum Tax, any tax deduction is moot.
