Bill Wood:
I found an old post ( http://www.peachparts.com/shopforum/showthread.php?threadid=8950 ) that talked about the AC dust filters on a 95 E420. Is it possible to retrofit these to earlier w124 cars? Even better would be if the activated charcoal and dust filters from newer Es could be adapted. Any ideas?

Carbon is the active ingredient here. I have pondered making a prototype using military chemical suits. Putting the activated charcoal between two pieces of a material molded to the shape of the intake. Sometimes I drive in chicken country which can make you puke fast. If anybody has tried it let us know. The key thing is density..to allow proper air flow.

The air boxes are different from the earlier cars to the later ones. I have not seen a way to do the conversion. I think you would have to replace the whole air box.

i use carbon filters for photostatic copiers. they can be shaped with a dremel tool. and would probobly do the job in a Mercedes.

Adam:
Do you have any info on where I could get these? Thanks in advance.

i can send you some with the charge of shipping
how many square inches do you need?
you can also get them from any cannon, minolta, recoh, sharp,xerox, savin, konica copier dealer.

Thanks for the offer Adam! I am measuring the grills now - they are curved, which might make it a problem, but let me see if I can work around it. If I can't, I am going to check with the people who make my home air cleaner (80 ft2 HEPA, 13 lbs Activated charcoal) and see how difficult it would be to make a "basket" of activated charcoal to suspend inside the AC intakes, or see if a 3M charcoal filter mask might work.