Original papers state that it was fitted with Zender KBA35028
The car has some special features indicating that first owner did have some special preferences when ordering the car.
Could it be a spelling error? But cant find a BMW zender that are close to KBA35028? Strange if it was 2 digits wrong?
Could it be KBA35038 that are the VW Golf Zender spoiler
And if it was two numbers wrong could it be KBA35382 for E28 with extra long sides going forward?
The Zenders I find used on E21 was:
KBA35037 - Typ?
KBA35347 - Typ 1.075.03.3
KBA35397 - Typ 1.111.03.3