There is an interest rate on the financing, a cost for payment insurance, and almost certainly a margin on top of both, but they've both been built into the price of the car.
It's very likely you could have gotten additional savings for paying cash up-front. It's usually cheaper to pass up these offers and negotiate the price down.
> It's very likely you could have gotten additional savings for paying cash up-front.
Payment method doesn't change your all-in cost significantly. The dealership has a minimum margin, and you'll pay it either on the front end (higher cash price) or on the back end (loan interest).
Generally speaking, car dealerships are in the business of selling loans -- not cars. If you want to pay cash they'll sell you a car, obviously, but the cost benefit of writing a check is way overblown.
It's very likely you could have gotten additional savings for paying cash up-front. It's usually cheaper to pass up these offers and negotiate the price down.