HI, trying to get full spec on these, there are a few versions, round,flat pins aux in ect, i am pretty sure land rover
stopped fitting them around 2005/6 but bmw carried on fitting them so it looks like you will need to source from a late bmw, they started with round pins and then went to flat, now apart from having a aux input and showing track names if you have the mp3 cd changer, what more can you get from them and how can you tell what's what V8 facelift Range Rover Autobiography 22" wheels.
1976 Harley Davidson Iron Head Sportster

Hi Dave, all BM54s can be upgraded. No need to buy a new one.

http://www.fullfatrr.com/forum/topic10342.html?highlight=bm54

The BMWs started off with BM24 round pin, then switched to BM54 round pin around 2000-2001. Then onto the Flat pin version.

There were also several FW upgrades - the most important would be aux-in capability as of build date of 9/2002.

EDIT Just noticed- old post! I wondered why Dave was asking this...  
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)