Make sure the trunk drains aren't clogged. I'm not sure about the
W126,
but on the W123 there's one at the bottom of each side bin. They show
up underneath as short rubber hoses. On my car they plugged and the
side bins filled up with water, greatly aggravating the condensation
problem. I unclogged them by sticking a screwdriver up into them and
wiggling it around.
Those drains, IIRC, are large rubber plugs with a triplet of holes
molded into them. The screwdriver will help them reach nirvana
together much sooner than normal. What I do is to squeeze/push
the whole thing out from the bottom up into the trunk. Then it
can be removed and cleaned, and the trunk well can also be hosed
(or bucketed) out to wash away all the crud. The big open hole
makes a good cleaning drain. Then I reinstall the good-as-new
cleaned rubber bit.
-- Jim
