[sandwi54]

First question is, how are you able to buy your father's 435i for $15,000-$20,000? Is he selling it to you at a huge discount?

You didn't state what stage of life you are in, how old you are, etc. But it sounds like you are just about to graduate from business school, so I am going to make an assumption that you are around 26-27 years old. At this stage of life, I really wouldn't dump money into cars; they are simply depreciating assets and after a few years, all that money is just going down the drain. Even a 435i brand new is an expensive luxury item for a newly graduate. You should focus on building a career, buy a house, and maybe start a family. Once you have all that done and have extra cash laying around, then maybe you can start thinking about putting a significant money into cars.

The US economy is going to enter another downturn in the coming years, and having as little debt as possible is what you should focus on. If I were you (just graduating from school), I wouldn't buy anything that costs more than $40,000. You can pick up a nice non-luxury brand sports car, fully loaded, for less than that.