re: What factors do you use to justify a car purchase?

I wasn't going for an exhaustive list in my post but of course the condition of current vehicle is critical. Besides an emergency justifying the purchase, I am interested in learning factors from others that could prove to be useful in the decision making.

For example, if I were to buy a car, I want to know the likelihood I will get 5 years or more out of it, will I have minimal maintenance costs each year, and will it overall pay for itself after a certain length of time.