I received the following helpful information from TurboTax:

The CT property tax credit is limited to $200 per return.  Since this credit applies to both residences and motor vehicles, if you have already reached the maximum CT property tax due to your residence, then the motor vehicle section will not appear.

However, you may also be able to claim a federal deduction for personal property tax paid for this item since this tax applies to personal property you own, is based on its value and is charged on an annual basis.  But, in order to claim the deduction, you will have to be itemizing your deductions to get any tax benefit.  

You can find this section in TurboTax under the Federal section -> choose Deductions and Credits -> scroll down to Cars and Other Things you Own -> select Personal Property Taxes and proceed with the entries.
Here is further information on the CT property tax credit, including instructions on entering this into TurboTax:

The credit is limited to Connecticut residents who paid qualifying property tax on their residence and/or motor vehicle AND one or more of the following statements apply:

You or your spouse is 65 years of age or older by the end of the taxable year.  
You claim one or more dependents on your federal tax return.
The maximum property tax credit allowed is $200 per return regardless of filing status. This credit can be used to offset only your 2017 income tax. You may not carry this credit forward and it is not refundable.

See Page 19 of 2017 Form CT-1040