I am no expert on finance but my two penneth is that the factors that influence my decision the most are whether I am buying new against used and the length of time that i intend to keep the car.
It seems that car companies have become complete magicians to influence their sales by offering structured payment packages that usually take an accountant to work out.
When I bought my current car, I had a shortfall of around 45k, as I was waiting to sell my other car, me being impatient, decided to finance that balance against the car on a straight forward HP deal, thus paying a set monthly interest. the rate was "fairly" attractive at 6.9% and as my intention was to pay it off quickly, I felt it would not be a big deal having this against the car.
As soon as I got the funds available, I tried to pay it off and by eck, they really didn't want to take the money, they seemed to want to do all that they could to ensure I kept the loan running.
As it turned out, I paid off half and decided to keep the rest for other things, so i did still leave a bit of finance on the car but not a great deal given the value. I intend to pay this off in a few months time.
I prefer the loan thing because I feel the car is mine to do what I want with if I get bored with it or fancy a change. i can even down grade if I need some money on the quick.
For those who like to keep the car longer and who have a bit more self discipline than me, I reckon the 3 year lease thing works really well but these do seem more structured towards new cars. this would never work for me as I like to think the car is miine and that i wont have to give it back after 3 years. my friend does it this way and always has a nice car to drive but I just feel it isnt really his. he isnt at all bothered, he takes out tyre and wheel
Insurance and includes service package and literally just drives the thing for 3 years and hands it back and goes again with anew one 3 years later.
We once did a calculation against his then new RR sport hybrid and we worked out that if you added all of the payment that he had made over 3 years, it still didn't exceed what would have been the depreciation of the car.
I.e. had he bought it new for cash and sold it 3 years later, it would have cost him more that what he has paid in monthly payments over the same term. So it clearly can work for some!