Are you thinking of Ozium? I've done that twice now, once since I've stopped the major leaking from the sunroof (the sunroof was also leaking as it was soaking the roof). Hopefully since I've removed the foam pad at the front passenger floor board it will take care of it. If not, may do the Ozium again since I've got the leak taken care of or may go ahead with pulling the duct work out. The air's been better since I've taken the carpet and carpet pad out so I'm thinking this may be the last piece since that foam on the floor board was stained black with likely mold.