Go to a buy here pay here dealer in your area, have them buy the car and sell it to you for a slight profit and they will finance you.
Email for how to do this if you are interested.
There is no such thing as a free lunch, however. You need to understand that BMW's need the most expensive maintenance and when they break down they are very expensive to repair.
Even routine maintenance will cost serious money, with tires, for example, running you close to a thousand for decent ones well mounted and brakes costing over $600 for a standard replacement job.
If you have to ask yourself if you can raise the money for the car, how are you going to afford maintenance and repair?
Is my Pan Am ticket to the moon still good?