If you are just trying to correct the make & model information, that isn't necessary. That information won't affect your tax return. i.e., the IRS doesn't care if it called a Nissan "Maxim", a 2016 "Maximum" or a Nissan Maxima.
If you need to change other fixed information about the car such as cost, type of vehicle, date purchased, date sold, etc., you will probably have to delete the Vehicle Worksheet (and associated forms) completely and re-enter it in the interview.
Why does this happen? Once you enter (or import
or transfer) certain information, the program creates or updates forms and
worksheets that use that information. In many cases, you cannot
"change" that information in the interview process - in a manner of
speaking, it has been "written in ink" on the forms. You have to
delete the form and any associated worksheets in order to correct.
See: How
do I delete forms in TurboTax Online?