I purchased a Lexus a couple of years ago where I was able to charge the amount due net of trade to my Amex Plat. Amount was around $37K. I called to get pre-approval, the transaction processed smoothly and I paid off the balance a couple of days later. OTOH, my local BMW dealer won't allow more than $3K to be charged, damn him! Doesn't hurt to ask or to even look around for dealers who are willing to feed mileage junkies like most of us FT'ers.