Rear Cabin Filter ?
 

I have a 2003 Mini Cooper S. In the rear area of the car on the inside when you open the hatch, there is what looks like a air return, or air exhaust vent. It has the material that looks like a plastic filter type.

What is this vent area, and does that filter like material need to be replaced?

I just got the car and am going thru routine maintenance and changing the items on the car that need to be replaced. The cabin filter was absolutely disgusting and encouraged me to replace the other routine maintenance type filters as well.

Does anyone know what that area below the inside hatch is, and if it is something I should be concerned about.

Thanks.

Damon