Z3 Roadster door diaphragm question

[Firelizard]

UK spec 1999 Z3 1.9 roadster: Is this slit in the driver's door diaphragm put in during manufacture? The straightness and nature of the cut would suggest that it is. I presume it's there to inspect and lubricate the window regulator.

 

[Duncodin]

Yep. Mine has that too.

 

[Firelizard]

Thanks for replying. I shall leave it as it is rather than glue it together

Rob