If your leaks are not solved by all the above measures, I would bet on the windshield rubber seal. The W123, all W124s I have owned, plus all the W124s my friends have, have had their windshield rubber seal changed at one time or another due to heavy water filtration.
The weather here (pure tropical climate) tends to fry the rubber seal and even the tinniest crack (not seen by the naked eye), tends to filtrate water by the gallons on heavy rain.
The W124s wagons also suffer from this problem on their back side windows and, less frequently, on the rear windshield.
To exchange the windshield rubber seal is not expensive and it really works miracles on curing water filtration. Although, if you use a non-authorized dealer, BE SURE they use the correct glue on the rubber seal. There is a special glue (some peculiar type of cylicone sealant) that MUST be used for Mercedes-Benz cars.
Just my 2 cents...
CL 500, 1998
S 500 L, 1998
E 320 T, 1995
Last edited by A. Rosich; 12-30-2002 at 02:15 PM.