When one views all the various BMW navigation equipment on sale, its often very tempting to but without the research and knowledge, you are liable to  being mislead and buying the wrong parts to make it work in your vehicle.  I  write from personal experience and it has been a long journey to make my system work!!

 Rule one, get a copy of the retrofitting diagram and instructions, this will detail exactly what is required, then at that point make sure when bidding for the items, they should all be nearly new as the old generations had issues and the screens size were smaller. They are also fitted in Range rovers/Mini,  so when searching check on those vehicles....

Finally if contemplating to Retrofit Bluetooth, same rule applies and make sure the ULF module is post 2003 as  the older variations had issues...check  this link as l found it very helpful.....