Between my wife and I we have had 5 BMW's, starting with a 69 1600. The short of it is that they are not as well built as they used to be. While they (for the mostpart) do not have major mechanical issues, you will find the newer cars tend to suffer from eletrical related problems. If you want the ultimate in reliability, your shopping should be limited to cars from Toyota or Honda. Where BMW still excels is in the are of driving dynamics and the feel of the cars. If you want to buy one, here are my recommendations:
1) Develop a relationship with a good independent BMW mechanic. Service from an independent will cost far less than from the dealer and often be higher quality.
2) Change the oil more than called for by the service indicators. Doing it once between the service indicators (about every 7500 miles) with the factory recommended synthetic is fine.
3) Ignore the lifetime service interval on the transmission fluid, change it every service 2 with the proper fluid and filter (automatic). The automatics have specific fluid requirements, in fact they used four different fluids so you have to pull the serial number to get the right fluid.
4) Do not buy a v-8. Repeat this multiple times. When you start to think otherwise, repeat it again. BMW builds great 6 cyl engines, their V-8's are more problematic and much more expensive to maintain and repair.
5) Have any car you purchase inspected by the independent mechanic you located in #1. I don't care that the car is "certified preowned" still have it inspected. There have been many certified preowned cars that have resprays, bent suspension components, non OEM brakes, etc. It is well worth $100-150 up front. If the dealer objects, tell them no deal and remind them that it has already been "inspected" by them, so your shop shouldn't find anything, right!!!
