The best way to do it is. Finance first. So you can get an invoice price or below. Put no money down. Makes sure who you finance with you don't get penalized for paying the car off. Make your finance for 72months. Then pay it off on the first payment. Reason being. If they see you coming in to pay cash right off. They will jerk you and make you pay msrp +ttl and trumped up fees. But when they finance, they work those fees in on a month to month basis and your payoff doesn't reflect anything but the amount you financed...
Then pay it off and you get them on the deal.