I have a 1999 E300TD that has an odd odor that drives me crazy. I started pouring animal odor neutralizer into the heat vents on either side of the tunnel and that seems to help. One thing that I noticed is that the stuff does not leak out onto the ground as anticipated. This leaves me to think that the drain hole(s) is plugged up.
Does anyone know where the drain tube comes out underneath the car? If I can find the tube (I assume a rubber hose of some sort) then I may be able to snake it out. The regular does of bleach might keep it open...
Don't know how much that might help you, but on my E320 the condensation water drains high in the center console. It drips down on transmission and all the brackets. I asked mechanic if this is correct, worrying about potential corrosion to exhaust and brackets, but he said, that in California cars don't corrode.