I agree with the fact that the 745i's have issues. Especially the first years. I also don't understand how going from an X5 to a top of the line BMW or MB sedan is going to "save" you any money. If you want to save money, sell your X and get an e46 or a 6-cylinder e39. Otherwise, keep what you have. Also, if you are just starting school I would imagine you are young. Why the big sedan?

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Profeshenal spellar