For all you 450i owners, are you aware of the additional air filter behind the dash? After a couple trips in some serious dust and dirt, I wantwd to give the airfilter a serious cleaning. After removing it from the airbox I found very little crud which took me by surprise. After washing and cleaning the inner and outer foam there was almost no crud! I then remembered the other filter behind the dash. After removing the front storage box, yes it is a little tricky to remove it but keep trying it does come out. The upper filter is to the left of center and faces rearward, you can reach your hand behind rhw vox and feel the course foam filter. There are two screws to remove rhat releases the frame holding the course filter material. This filter had all the crud I was expecting to find. After a good wash and dry all is good again. When ir is time to clean that air filter dont forget the one behind the dash, this is the one where most of the crud will be contained
