My question is about the vehicle tax credit specifically, but can be answered by laying out the general order that credits and withholdings are applied to the tax liability. For instance:

Assume these totally fictional numbers -

Tax liability = 10,000
Child credit = 2,000
Vehicle credit = 7,500
Tax withholdings = 10,000

What is the order that credits and payments are applied? Would it look like this:

10,000 (tax owed)
-9,500 (total credits)
500 (tax liability)
-10,000 (withholdings)
-9,500 (refund)

Since the vehicle credit is nonrefundable, it makes a huge difference if it is applied first or last. If first, that means a $9,500 refund; if last, no refund.

Any help?