Have a 2001 300M which is leaking water into the interior of the vehicle. We have replaced the rear driver-side door gasket and the driver-side door gasket and it is still leaking water into the car.
We thought it might be the XM antenna which is on the roof and is routed into the interior via the window gasket and we moved that too, to the inside and still it leaks.
We have had mechanics look into it and they cannot find any kind of leak that would allow water from heavy rain to enter the car. However when it rains, we have at least a good inch of water puddled in the rear(depending on how the car is parked in our driveway) or in the front floorboards.
I've searched the car and cannot find water dripping or a water trail. Is there some kind of gasket near the firewall or in the dash or near the the window that would allow water in? In at a loss at this point.
mechanics have suggested that it might be getting in from the underbelly of the car when we drive, but that's not the case. Our last heavy rain the car was parked for 4 days while it rained and it filled up with at least 2 inches of water.
I might add that it is only the driver-side that is getting wet. Nothing on the passenger side. Completely dry front and back.