One problem related to car will not start has been reported for the 2007 BMW X5. The most recently reported issues are listed below.
In July 2007 I purchased a brand new, fully loaded 2007 BMW X5 4. 8. Back then, it was my dream car. Now, it is a nightmare. From the beginning, we have experienced different minor issues with the car (dvd player not working, for example) that the dealership fixed. However, once we started having problems with the car not starting, that was no longer a "minor" issue. The first time the car did not start was around thanksgiving in 2008, only a little more than a year after I had purchase my car. By the summer of 2009, the problem got worse and half the time the car would not start. We finally took the car in (Nov 2009) and the dealership told us the battery was death, and they replaced the battery at no charge (warranty). Everything was fine until March 26, 2011, when I was ready to leave and my car did not start. At this point, I was so frustrated that I immediately called the dealership and told them I did not want a car that doesn't work parked in my garage, so I was going to drop it off. It was a Saturday, so I did not hear back from the dealership until the following Monday, only to tell me that the battery was very low and needed to be replaced again. They also told me that it was because of my driving habits, because most of my trips are very short (less than 5 mi) trips. I asked them if I needed to change my driving habits in order for my car to work, and they said "hmm, yeah". Really??? to top it off, since the problem was caused due to my "driving habits", I needed to pay for the replacement of the battery. I believe the design of the of the electrical system has problems. No car, especially no high end car, should not work because "it is not driven enough". Did BMW engineers finished the design and said, it is done, but it will only work if you drive it enough!. BMW needs to fix this problem and stop blaming the car owners for their poor design.