Get your taxes done using TurboTax

I can update both fields in my version of TurboTax CD/Download.

Have you tried Forms mode?

1. Tap Forms in the top right corner
2. In the left column, find Tax & Int Wks
3. Line 3a should allow you to enter or change your vehicle info
4. Tap Step-by-Step in Forms when you are done to return to the interview mode