First of all, you shouldn't buy a car for that much unless the money is pocket change. Dave Ramsey, if you listen to him long enough, basically teaches against buying something (a car, house, etc.) that you really can't afford unless you have the money to "throw" away.
That being said, the major problem I see with leasing is the mentality that you need a new/nice car every couple years.
A majority of people in this world do not NEED a new Escalade. A nice, slightly used vehicle can be purchased for cash for no more than $20k. If that guy came to me for advice, I'd say buy a nice/relatively new used car for $20, pay cash, and put the $50k that you were going to spend for a new car and invest it.
Leasing is stupid IMHO.