Trim behind rear wiper on W211 estate

[sorrel]

Hi!

Have a small problem, but it's annoying me!
The metal (almost looks like tin) black painted trim behind the rear wiper on my W211 estate has begun seriously corroding. Does anyone know if this trim easily comes off, is replaceable or in fact can the car live without it, as I notice C Class estates don't have this little metal trim, the wiper simply comes out of the glass.

Thanks!

sorrel

 

[5pares]

I think its part of the rear window. Is it worth taking it into a dealer?it maybe covered on corrosion warranty.