I also have a round black plastic drain pan that prevents you loosing the drain plug, though I have never used it yet on the Mercedes 300-E. I though is that it may be a good idea to alternate from the top sider to the drain pan . I can see why the top sider is so popular , as it is easy to use with out any mess.

however real mechnics have to get messy in order to acknowledge the jobs been done and check the underside of the car.

Bob Geco