There are three questions here :-
(1) Do you have the money to be able to afford to buy the car outright ?
(2) If yes, do you get a better rate of interest by financing it or is the money better off spent on the car ? That is to say, if the dealer is offering 0% finance then its better to take that and keep the money in the bank. I have a friend who bought a top of the range Mercedes and was offered finance at 2.9% APR finance. They CAN do it if they want to.
(3) If no, then finance may be the only way to afford the car that you want.
Either way, and whatever finance deal you opt for, you always end up paying for the depreciation of the car. This is always the silent killer that people often forget about. Owning the car at the end of the agreement doesn't really matter if you haven't paid for any equity because you still have the money that you would have paid for the equity with, if you see what I mean ?