Installation of cabin filter with wings

[Letrix]

Hi All
I recently replaced my cabin air filter. The filter I bought is shown in the picture. It has an extra edge on the side that goes toward the rear of the car and an edge located where the slot is. I'm not sure how this extra edge should be folded. I folded both edges upward (see photos). This created a gap between the bottom of the filter and the slit. If I understand correctly, air enters through the round hole, then through the filter, and down. So there shouldn't be any gaps? Could you please tell me if I installed it correctly?

 

[JvdBosch]

The round hole is part of the engine noise circuit, to hear some more engine noise in the cabin. There is a pipe which connects to it, did you remove it or was it never there? I replaced the filter cover with one without the hole and removed the pipe. It seems to me this is a sort of air leak. Other than this, I think you installed it correctly.