Hi everybody,Need your advice. Been following this forum for quite some time(since before it moved), now I'm finally financially ready to get a UDM.I'm looking for a E39 523i around 97/98. I need some advice before I go calling at numbers. What is the first thing that I should look for when I see the car?Are there any known problems with the make of these years?What are the difference between the CKD and CBU models?Where is a good place to get it checked? What is the yearly maintenence cost like?Any other thing I should know?Any advice on this is greatly apreciated. Thanks in advance.