had the exact same problem with my '94 E320 Cpe shown below. Thought I was crazy!
I'd clean it off and drive the car. No leak. After sitting a few days, I see a seepage of oil from the front cranksaft seal. It wasn't alot but would run down the front of the pan and collect on the drip shield.
By the way, this was AFTER the seal was replaced. Was ok for about a year or so. Then it started to leak again.
I been told since that the inline six cyclinder 3.0, 3.2 engines did that alot.