The EV credit can only be claim in the year you put the EV into service (2023). any EV credit in excess of your tax liability for that tax year (2023) would be lost since there is no carryback or carryforward. Besides for that amount of EV credit you probably would be spending $30K or more for the vehicle which the IRS could seize if you fail to pay your past tax liability. What your tax advisor is saying by getting the EV credit you lower your 2023 tax liability and that tax money you save (could be much less than $7500 because the benefit of the credit depends on your tax liability. if it's only $4K before the credit - certain taxes and credits can affect the tax liability to which the credit can be applied - the credit will only save you the $4K - for example the credit can't be used to offset self-employment taxes) can go to pay off your 2021 balance. if you need a new vehicle and have the money to shell out for it maybe it makes sense. personally if i had the money and didn't desperately need a new vehicle i would pay of the IRS because penalties and interest are continuing to accrue
