CD changer questions

["Mike Theuri" <mikesoft@xxxxxxxxxxxxxx>]

I have looked through the archives on the net and on the digest and 
found basic information on what aftermarket changers one could use
as well as the interfaces they need (BMW-PIO/M -- Where can I buy this ?) 

I am now currently looking at OEM CD Changers. This happens to be 
a used unit from a 93 325. My car is a 93 318i and I was wondering if 
the differences in the head unit. Pioneer vs Alpine would make this 
particular changer incompatible with my head unit or is any OEM 
changer compatible with any head unit ? Thanks 

Mike Theuri

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