…where did the oil come from?

Today I have noticed with horror that there are some (approx.10) oil stains in my garage. I then went to the search immediately where the oil could come from. I found a “wet” spot on the right side (passenger) in the front, below, the cooler. The floor covering and the overlying parts were smeared with oil, but not very much that some oil has dripped down. I have examined all hoses for possible leaks but found nothing. I also controlled the hoses from the servo pump, nothing. But where does the oil come from? The car was in inspection about three weeks ago and about two weeks ago the complete lumping was changed. If something had been there, you should have noticed that.