Just come across this interesting post on Facebook regarding an alternative approach to adding a second ear to the rear diff without any machining of the diff case or welding of the supporting bracket so far. See what you think.
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BMW ///M Roadster Enthusiasts | This is my 1998 M Roadster | Facebook
This is my 1998 M Roadster. My spot welds are still intact. I got a right hand side second ear diff kit made and installed. You can installed it yourself in your garage 👌👍. It’s a perfect fit;...