So I am one of those people that won't have to pay anywhere close to 7500 in taxes due to other credits. However, a family member (my Grandfather) pays quite a bit of taxes a year. If he cosigned a loan on the car with me, could he claim the tax credit for himself, without being on the registration? I don't have a problem putting him on the registration if needed, but he lives in VA and I am in WA state, meaning I don't pay sales tax. Could someone who has claimed the credit explain to me what is required for ownership?