At 120,000 the transmission had an default error. While driving I would hear a thump and then the car will go into limp mode. The limp mode caused the car to shift in a different gear and on take off from a stop the car would still be in a different gear. However, when I turn off the car and then back on, the car returned to normal and then proceed to go back in limp mode. I was told I needed a new transmission. Spent $5500 and the transmission was fixed two days later the same thing. Then I was told it was the gearbox had it fixed, a day later the same thing happened. Then I was told it was probably the wiring going to the transmission, had it fixed and the same thing happened. At this point, I had put too much money into the car. Not only has my car had this issue but many more BMW cars are having the same issue. I believe that BMW needs to view this issue and fix it. These cars are suppose to be top of the line and the cost of these cars should ensure that this type of issue should not happen. I understand if there was a need for a new alternator, sensors, rotors, spark plugs but, this is a big issue. I had a Nissan Maxima and not once did I have a serious problem as this. I had 190,000 miles on the car and it was still going. I will never buy a BMW again.