Originally Posted by 87tdwagen

As far as I'm aware, this was never offered as an option on the W126. It is possible that the European EPC "might" have one listed but likely in the halls of unobtanium by now. There are some write ups on MB world regarding making your own, but in order to add a true cabin filter will require quite a bit of work to get a proper 30mm thickness filter to fit. On the other hand, you could easily fashion a workable assembly using a general household HVAC washable filter assembly. Home Depot and the like will have a cut to fit HVAC filter that comprises of various filter mesh media, and a couple of hard plastic grids to encase the media so that it stays put and not sucked into the evap. This can all be sized and trimmed to fit the space that you have. Now understand, that the CFM rate is quite high and the media cannot filter down to paper cabin filter levels, but it will do a great job of keeping lager debris from entering, and best of all, washable, so once you've made it, should last you as long as you need it to.