Where could I find this part?

[Damien]

Hello,

I'm looking for air vents (is it the correct name?) for doors' window. I want something similar to the ones in pictures below, on the Ultima, or eventually like the ones on the Audi Quattro. Do you know where I could find these parts? At Ultima's, they told me that they don't sell spares...

Thanks,
Damien