Deductions & credits

That’s a different story, since you’re talking about your own small business, as opposed to itemized deductions.  

When you’re self-employed and use your car in your business, you’re allowed to claim the business portion of your state and local personal property taxes on your motor vehicles, as a business expense.

Please see Personal property taxes under Car Expenses in IRS Publication 463, Travel, Gift, and Car Expenses for more information.