Thanks Steve! This info is great. What I would really like to find is a serial number chart for Beckers. I found it when I first started researching the post style becker’s, but I can’t find it now. Multiple people mention that the serial decoding is similar to blaupunkt, but the information is difficult to find.Heck no, no offense taken and I didn't intend to come off combative, you can disparage my car anytime! The BMW accesories book of 1973 shows a post-style Becker as an option, is there a site that dates the radios by serial number? I could not find one a while back. That link you posted shows what was appropriate for Mercedes, not BMW?
As far as the info, I presume that the date ranges are for the radios not the vehicles. I found other references to that site where folks make the same presumption, but it is difficult to confirm. I’ve used BMW adverts to backup my observations before, so why stop now?!!