What you typically get for a refund is immaterial for the discussion/use of the EV credit and you don't need to change anything on your withholding for this tax year and you really should not make any withholding changes. What you do need to do is have enough TAX LIABILITY to use the EV credit in full since any unused credit is lost.
So start by looking at the 2021 form 1040 line 18 ... that is the amount on the 2021 return that could be negated by the 2021 credit if you had bought in 2021. Estimate how much tax you will owe for 2022 and if the EV credit is higher than the line 18 tax bill then you need to increase your tax bill to fully use it up and not lose any of it. Ways to increase income is to earn more, sell stock at a profit, take a taxable IRA/retirement distribution or do a ROTH IRA conversion, etc.
