Here's something I thought of today that might work for you. I wasn't gonna use my Naugahyde covered kick panels again so I decided to modify them a bit and see how it turned out. Just cut away everything that's not part of the vent structure...
This one is just rough cut for now, especially around the pillar...looks pretty good I think. To finish, just paint it and add some rubber edging, or glue some carpet on it.










