As shown by previous answer, this is correct:
If you're actually using TurboTax Self-Employed, you'll have to go through the business section reporting your income and expenses in that section (Schedule C).
Included therein, is Business Vehicle Expense where you will enter the costs for your car.
I just wanted to add that you also see if you can get a larger deduction with this option "Yes, I'd like to see if my actual expenses give me a higher deduction" .
Good luck.
