I wanted to try an open filter, to hear the induction sound and the blowoff sound. I went with a big velocity stack type filter. Although it sounded nice, I already reverted it and went back to the original airbox.

Volvo S80 2.4T Fitting a Velocity Stack Open Cone Filter

Volvo S80 2.4T Fitting a Velocity Stack Open Cone Filter

Volvo S80 2.4T Fitting a Velocity Stack Open Cone Filter

Volvo S80 2.4T Fitting a Velocity Stack Open Cone Filter

And it looks like this again

Volvo S80 2.4T OEM Airbox