The fees would be insane.
Everytime I’ve bought a car in the US I use my credit card to pay the maximum amount down and it’s always been $5000. Hard to believe a dealership would let anyone spend $100’s of thousands on a credit card when they’d have to eat the fees or pass those fees on to the customer.
And anyone who has the ability to put 100’s of thousands on a credit card can easily do a wire transfer which doesn’t cost the dealer anything.