My 1990 240 DL has really wet carpet in the rear, passenger floor area when it rains and has been parked on the slight uphill road in front of our house. It also gets wet carpet in this area (but not as bad) and in the trunk when parked on level areas in the rain. I suspect the front and back glass rubber gaskets are leaking. Anyone have any other ideas? Any suggestions for stopping these leaks, or for tracking them down? The windshield was replaced about three years ago, the rear glass is original.

My 1990 760 Turbo has the same water problem in the front passenger side. It gets drenched if I am parked in the rain, but oddly enough, it's fine if I'm driving in it. I wish I had further advice!

the windshield wiper motor is mounted below the outside fresh air vent. The seal around the motor will leak and run down to the floor. Loosen the motor mount bolts and check for a good seal between the back of the motor and firewall. You may need to disconnect the shaft retainer clip to pull the motor out far enough. I had the same problem and this fixed it. pull the glove box and upper carpet loose and run some water through that vent to be sure, it will come out at the motor shaft area if thats the leak. I bought some foam water proof sealant and this did the trick.

Thanks for the advice. You may be right. That would be about the right place, given the slope of the parking area -- water would just run straight down the inner panel and back to the rear floor area. I hate working under the dash of a car, but that always seems to be where I end up. I'll check the this and see what I find.