If I paid Excise tax on a new vehicle in South Dakota, can I claim that as sales tax? Note: South Dakota doesn't have income tax, so that's why I'm using sales tax.

No, excise taxes are not deductible as sales tax; however, some state excise tax is deductible as personal property tax on Schedule A, itemized deductions, in place of car registration fees.  See the following article to read the condition for this deduction:   The article is pretty short.

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