Alternator/generator/regulator problems of the 2003 BMW X5

I purchased the vehicle used, I have had it for about 5 months and have had some serious problems (steering column, window regulators, engine, and coolant leakage). I see where these issues seem to be consistent with the vehicle, but am having a hard time getting the recall work done. I can's afford to spend a lot on this car, but I feel like I may have more than I bargained for. My extended warranty is not paying for much !!! help.

BMW x-5 has caused two accidents by spontanous accelleration - after first accident BMW was contacted and engineers kept vehicle and determined that cause of accident driver error-we paid for repair of vehicle. Same "acceleration" happened about six months later on January 7 sending car crashing through front of building - only by miracle people weren't ingured in these accidents (the building was a a retail store). This is a leased vehicle and we don't know what to do. Lso, these incidents have caused our insurance to skyrocket.