Got it, sorry.
The long answer is, if something of that shape with clips is put on, it will create turbulence, therefore generating wind noise. The sunroof has its own deflector that does a decent job at moderating the airflow with the sunroof open. I had it open today on the highway doing 120 Kms/hr and I could barely feel the air coming in.
The short answer is, like somebody already said, "remove the said deflector".