How about trying a professional AIR-IONIZER that some of the used car dealers use. I had a friend that sold AIRSOURCE?? air cleaner/ionizer products both residential/commerical. He said dealers would take their worst smelling cars...prior to them buying the ionizer from him..they would "test" the product out.. Plug the unit in overnight with windows rolled up...and odors disappeared by the next working day. I've never used the product/(never had too) but maybe others could comment on similiar products.So far I've steam cleaned the seats, carpet and headliner, coated those areas w/fabreeze left the doors open until it dried, then wiped it all down again with a damp sponge w/a little vinegar and re-applied the fabreeze and let it dry again. I the cleaned all the hard surfaces with cleaner, cleaned the glass and poured a little clear Cleanaire Deordorant from Advance Auto in the fresh air intake and in the windshield wiper fluid. It's alot better but after a week or so it comes back. I wish I could clean out the duct system but I can't figure out how to do it. What's the name of the product you referred to?