Leasing a car is probably the most expensive way of using transportation. DO NOT DO IT! Think about it, you're essentially renting a car from a dealership. Look at renting a car for 30 days and see how much that would cost. You might find that you're paying around the same amount as if you were going to perpetually rent a car, which is what you're doing. You own nothing after the lease is done.
There is one exception to this rule though. That is if you're one of those people who "needs" a new car every two years. This is crazy on an individual basis, but a lot of companies do it for good reason. They can usually expense it off faster for a tax advantage, plus they can swap out their models with a faster turn around. This is important to some companies for some reason.
The cheapest means of car transportation is to buy a used reliable car and hold it for 10 years or longer. If you buy a new car be sure to hold it for at least 5 years.