Not a card that you have.

The best card would be a card that offers a good signup bonus for spending a lot of money within the first few months.

The earning on signup bonuses tends to dozens of times better than the spend on cards you already have.

With any of the cards you listed, you'll earn at most 5000 miles or 5000 points with normal spend of $5000. But there are cards out there that will give you 5x, 6x, or 10x that much if you do the same $5000 spend on a new card.

...

I don't know of any car loan that can be paid off with a credit card. Car loans are with banks, and banks never credit cards as payment for other accounts, except in the special case of a balance transfer (but most balance transfers don't earn any miles or points).

The only way to do is it use Manufactured Spending, which is a technique thus called because you can use it whether you have a big payment to make or not, because (in exchange for fees and legwork) you can turn credit card purchases into cash, which you can use to in turn pay off the same credit card (if you aren't trying pay off a car loan instead).

So don't worry specifically about the car loan. Either get into Manufactured Spending, in which case it doesn't need to be tied into a car loan, or if you're not going to get into Manufactured Spending, there's no other way to pay for the car loan with a credit card.

Manufactured Spending can be a complex subject, so there's a whole forum on FlyerTalk dedicated to it:

http://www.flyertalk.com/forum/manuf...-spending-719/

(But once again, Manufactured spending is 5x to 10x to 25x more "profitable" with signup bonuses than with cards you already have, given that you have to pay fees to do Manufactured Spending, and they're related to the amount of spend, not the amount of earn, so the more you earn per dollar the less the fee is relative to what you earn.)