A.: You raise two essential questions. First, is selling the vehicle on the open market a smart way to go? It may or may not be.
If you are concerned about your car's ability to maintain its value or fear the engine is ready to leave us, I would feel more comfortable trading the car in and letting the dealer handle it. In today's world, used cars are doing relatively well, and you should be able to get a decent return.
However, if you wish to sell it yourself, you can still think about trading it in if it doesn't work out.
Second, as to the down payment, you're right: The more you put down, the less you finance and the quicker you pay it off. You’ll want to shop for financing, as well.
If you pay cash, borrowing the money elsewhere, oftentimes you can get a substantial reduction in price or a cash refund.
Either way, the answers are not always clear. Who said this should be easy?