I did notice some oil on the garage floor following the last oil change. I have always had a few drops on the floor but this was more than usual. I think that the person at the shop must have checked the power steering reservoir and did not retighten the lid properly. What I thought was oil must have been P/S oil/fluid. The side of the reservoir looked like it had a oil stain down the side, and the puddle on the floor was on that side of the engine. By the way, I was surprised to see that the "fluid" was black, not clear or red like other standard P/S fluid. Is this just unique to Mercedes?