Issue with the wing mirror cover of the W203 2006 C180 Kompressor

[newjimmy54]

My cherished W203 C180 has faced scrutiny from the MOT authorities this year, requiring rear pads and discs (along with a calliper), rear shocks and springs, rear droplinks, and front droplinks and lower suspension arm. The driver's side mirror indicators have malfunctioned, since just one bulb is operational. I appear to be experiencing a power drain, as the battery depletes within two days, despite both the battery and alternator testing OK; however, this is not an issue pertinent to the MOT.
I completed the task but removed the mirror cover independently, as YouTube tutorials said it was a straightforward procedure. I have replaced the entire indicator component as the original was fractured; it fits properly and is flush. I am unable to reattach the cover securely. The metal clip is intact and undamaged; however, the plug for the indicator seems slightly loose, as if it will not properly fit into the new housing when attempting to secure the cover.
Initially, I believed the new indicator component did not precisely correspond to its aftermarket counterpart; but, upon comparison with the old version, it is indeed a match. I meticulously disconnected the plug to verify its functionality, and it operates correctly as the indicators illuminate. I have examined the cover for damage and found none. Does anyone have experience with this type of issue? Is there something evident that I am neglecting? The mirror glass is satisfactory; it folds and operates correctly. It is the final need I must fulfil before returning it for retesting. To qualify for a complimentary retest and avoid a comprehensive new examination, I must do this by Tuesday, which marks the tenth day since the failure. Can someone inform me whether a Mercedes specialist (we have one nearby in Huddersfield) can repair it, or should I seek to acquire a new entire mirror unit?

Could anyone with expertise in these mirror covers provide guidance, please?

[MercedesMan98]

Consider warming it on a heater; this may enhance its elasticity.

[newjimmy54]

Thank you; that is certainly worth attempting.

[RuthHimmic]

I encountered a comparable problem 18 months prior with our 2005 W203 C200 Sports Coupe.
My spouse damaged the N/S repeater indicator light.
MB stated they were unable to provide the new component... Merely a substitute mirror

I discovered an aftermarket component on eBay at a fair price.
It appeared satisfactory; nevertheless, it required some filing to fit inside the mirror cover.
I encountered the identical issue as the first poster; I was unable to secure the electrical hookup.
The vendor reimbursed my funds.
I acquired a pre-owned component from Prestige of Oldham.
Extremely accommodating individuals / Fair pricing.
The component was installed without complications.
The electrical connector engaged seamlessly.
Outcome!

[newjimmy54]

I brought it to a local independent shop today and was unable to secure it completely, suggesting I encountered the same issue; the aftermarket strip is not entirely compatible. We ultimately removed the clip on the plug that secures it in position, allowing us to connect it and position the cover sufficiently to tape it in place for the MOT inspection. I fortuitously discovered an individual on eBay selling a cover with an indication for £15, which is expected to arrive by Friday.

[RuthHimmic]

Best wishes for the new component.
I trust it will fit and operate satisfactorily.
The flexible attachment of the electrical connector is intended to provide sufficient movement for self-alignment with the connector guide on the mirror cover.

I consistently hold my breath when fitting it.
However, it appears to be effective.

[RuthHimmic]