Where do I input the payments I made for car tags?

To enter Car registration fees -

Click on Federal Taxes (Personal using Home & Business)
Click on Deductions and Credits
Click on I'll choose what I work on (if shown)
Scroll down to Cars and Other Things You Own
On Car Registration Fees, click on the start or update button

Or enter car tags in the Search box located in the upper right of the program screen. Click on Jump to car tags

For personal expenses, you enter the amount of tax based on the value of the vehicles, under Federal Deductions and Credits. Locate Your Home. Select property taes.

Topic no. 503, Deductible taxes states: Deductible personal property taxes are those based only on the value of personal property such as a boat or car. The tax must be charged to you on a yearly basis, even if it's collected more than once a year or less than once a year.