Credits for New Clean Vehicles Purchased in 2023 or After | Internal Revenue Service (irs.gov)
see the link you'll notice that she can use 2022 AGI (prior year) as long as it was under $150,000
the vehicle has to be titled in her name.
If your filing status changes between the preceding year and the current year, you may claim the new clean vehicle credit if your modified AGI is less than or equal to the threshold applicable to your filing status for the preceding year or current year.
if you tried MFS for 2023, it's allowed as long as her 2023 AGI is below the $150K, but jointly you might end up with an increase in tax liability more than the credit would save you.
