Battery problems of the 2005 BMW X5

1: we bought this BMW 2005 X5 in June 2008 and brought it into the dealership in June 08 for routine full electrical and mechanical diagnostic check. Upon completion of repairs/diagnostics, which took almost a week, dealership told us that there were no electrical and mechanical issues. Within just a few days after receiving delivery of the vehicle after the "clean bill of health" from the dealer, the car completely died. This incident occurred in the morning right before work resulting in logistical, financial, and safety issues. The car had to be jump started and the battery was replaced. In addition, the fuel gauge does not work properly and was brought up multiple times with the dealer without resolution. Within a few days the same situation occurred, again resulting in logistical, financial, and safety issues and the battery was replaced. Over the next week, we noticed about 16 other electrical and mechanical issues and brought the car back to the same dealership. After receiving the car back from the dealership, we continued to have problems with the car. About 2 months later, the battery had to be replaced again as the car died again. Within another month, the car died yet again! again, it was the battery. Again, the battery had to be replaced. 2: the failure is, amongst multiple other issues, a chronic battery drain. 3: last repair, about 2 weeks ago, the tcu unit was replaced, along with the battery. So far, we are on our 5th battery in 4 months in a newer BMW X5! our fuel gauge still does not read full when full and is inaccurate. Dealer states that "this is the way all Bmws are made".