Are there any other numbers on the radio casing...and is the number 8690b correct?
There is a 8960 (Blaupunkt) model with a BMW badge.
If it is a Blaupunkt, then there should be a model number beginning with 7 *** *** ***
You could try 2532
If not try 3553
Please post back here with any further Serial Numbers and also whether either of the above two codes were successful or not
RegWorts
July 2008