Thanks for the Input. There are no drain holes and I'll try your method of covering the tail pipes while checking for leaks when I get the chance. I may simply take the car to a Mercedes dealer and have it checked out.
The reason the 300E has only got 53K on it is that we had a 190D that was our daily driver and the 300E was used for long trips. I've thought about getting a new car but can't find anything worth spending $40K more for. Maybe the 2003 E430 but I'll have to wait and see.
Meanwhile, my new daily driver is a golf cart:-)