any idea what this is?

[Schneller 3er]

It's the alarm horn that connects to the 13 button OBC. Early cars had it mounted next to the strut housing, just like yours. Late model cars had it mounted underneath the car, right behind the driver side horn. It will be covered by a metal bracket.

[ScHpAnKy]

It's the alarm horn that connects to the 13 button OBC. Early cars had it mounted next to the strut housing, just like yours. Late model cars had it mounted underneath the car, right behind the driver side horn. It will be covered by a metal bracket.

ah-ha! that explains why I've never seen it before, this is my first early model